diff --git a/helper.php b/helper.php
--- a/helper.php
+++ b/helper.php
@@ -1,788 +1,830 @@
 <?php
 /** 
   * Helper Class for the DAVCard plugin
   * This helper does the actual work.
   * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
   * @author  Andreas Böhler <dev@aboehler.at>
   */
   
 // must be run within Dokuwiki
 if(!defined('DOKU_INC')) die();
 
 class helper_plugin_davcard extends DokuWiki_Plugin {
   
   protected $sqlite = null;
   
   
   /**
     * Constructor to load the configuration
     */
   public function helper_plugin_davcard() {
-    $this->sqlite =& plugin_load('helper', 'sqlite');
-    global $conf;
+
+  }
 
-    if(!$this->sqlite)
-    {
-        if($conf['allowdebug'])
+  /** Establish and initialize the database if not already done
+   * @return sqlite interface or false
+   */
+  private function getDB()
+  {
+      if($this->sqlite === null)
+      {
+        $this->sqlite = plugin_load('helper', 'sqlite');
+        if(!$this->sqlite)
+        {
             dbglog('This plugin requires the sqlite plugin. Please install it.');
-        msg('This plugin requires the sqlite plugin. Please install it.');
-        return;
-    }
-    
-    if(!$this->sqlite->init('davcard', DOKU_PLUGIN.'davcard/db/'))
-    {
-        if($conf['allowdebug'])
-            dbglog('Error initialising the SQLite DB for DAVCard');
-        return;
-    }
+            msg('This plugin requires the sqlite plugin. Please install it.', -1);
+            return false;
+        }
+        if(!$this->sqlite->init('dvacard', DOKU_PLUGIN.'davcard/db/'))
+        {
+            $this->sqlite = null;
+            dbglog('Error initialising the SQLite DB for davcard');
+            return false;
+        }
+      }
+      return $this->sqlite;
   }
   
   /**
    * Retrieve a contact by specifying details like the name
    * 
    * @param int $id The address book ID
    * @param string $type The type to look for
    * @param array $params The parameter array
    * 
    * @return array An array containing the results
    */
   private function getContactByDetails($id, $type, $params = array())
   {
     $write = false;
     if(strpos($id, 'webdav://') === 0)
     {
         $wdc =& plugin_load('helper', 'webdavclient');
         if(is_null($wdc))
             return $this->getLang('no_wdc');
         $connectionId = str_replace('webdav://', '', $id);
         $settings = $wdc->getConnection($connectionId);
         
         if($settings === false)
             return array('formattedname' => $this->getLang('settings_not_found'), 'result' => false);
         if($settings['type'] !== 'contacts')
             return array('formattedname' => $this->getLang('wrong_type'), 'result' => false);
         
         $entries = $wdc->getAddressbookEntries($connectionId);
         $write = $settings['write'];
     }
     else 
     {
         $acl = auth_quickaclcheck($id);
         if($acl > AUTH_READ)
         {
             $write = true;
         }
         elseif($acl < AUTH_READ)
         {
             return array('formattedname' => $this->getLang('no_permission'), 'result' => false);
         }
         else 
         {
             $write = false;
         }
         $addressbookid = $this->getAddressbookIdForPage($id);
         $entries = $this->getAddressbookEntries($addressbookid);
     }
     foreach($entries as $entry)
     {
         switch($type)
         {
             case 'structuredname':
                 $contactdata = explode(';', strtolower($entry['structuredname']));
                 if(count($contactdata) < 2) // We need at least first and last name
                     return array('formattedname' => sprintf($this->getLang('contact_not_found'), $params['firstname']. ' '.$params['lastname']), 'result' => false);
                 if(($params['lastname'] != '') && 
                     ($contactdata[0] === $params['lastname']) 
                     || $params['lastname'] === '')
                 {
                     // last name matched or no last name given
                     if(($params['firstname'] != '') && 
                        ($contactdata[1] === $params['firstname']) 
                        || $params['firstname'] === '')
                     {
                         // first name matched too or no first name given
                         $info = $this->parseVcard($entry['contactdata'], $entry['uri'], $write);
                         return $info;
                     }
                 }
             break;
             case 'formattedname':
                 if(trim(strtolower($entry['formattedname'])) == $params['formattedname'])
                 {
                     $info = $this->parseVcard($entry['contactdata'], $entry['uri'], $write);
                     return $info;
                 }
             break;
             case 'email':
                 $info = $this->parseVcard($entry['contactdata'], $entry['uri'], $write);
                 foreach($info['mail'] as $data)
                 {
                     if(trim(strtolower($data['mail'])) === $params['email'])
                         return $info;
                 }
             break;
         }
     }
     return array('formattedname' => sprintf($this->getLang('contact_not_found'), $this->getLang('invalid_options')), 'result' => false);
   }
 
 
   /**
    * Retreive all address book entries
    * 
    * @param int $id The addressbook ID to retrieve
    * 
    * @return array All address book entries
    */
   public function getAddressbookEntries($id)
   {
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false;  
       $query = "SELECT contactdata, uri, formattedname, structuredname FROM addressbookobjects WHERE addressbookid = ? ORDER BY formattedname ASC";
-      $res = $this->sqlite->query($query, $id);
-      return $this->sqlite->res2arr($res);
+      $res = $sqlite->query($query, $id);
+      return $sqlite->res2arr($res);
   }
  
   /**
    * Retrieve a contact by the structured name
    * 
    * @param string $id The addressbook ID to work with
    * @param string $firstname The contact's first name
    * @param string $lastname The contact's last name
    * 
    * @return array The contact's details
    */
   public function getContactByStructuredName($id, $firstname = '', $lastname = '')
   {
     return $this->getContactByDetails($id, 'structuredname', 
         array('firstname' => strtolower($firstname), 'lastname' => strtolower($lastname)));
   }
 
   /**
    * Retrieve a contact by e-mail address
    * 
    * @param string $id The address book ID
    * @param string $email The E-Mail address
    * 
    * @return array The contact's details
    */
   public function getContactByEmail($id, $email)
   {
       // FIXME: Maybe it's a good idea to save the e-mail in the database as well!
       return $this->getContactByDetails($id, 'email', array('email' => strtolower($email)));
   }
    
   /**
    * Retrieve a contact by formatted name
    * 
    * @param string $id The address book  ID
    * @param string $name The contact's formatted name
    * 
    * @return array The contact's details
    */
   public function getContactByFormattedName($id, $name)
   {
       return $this->getContactByDetails($id, 'formattedname', array('formattedname' => strtolower($name)));
   }
   
   /**
    * Retrieve a contact object by its URI
    * 
    * @param string $ID The address book ID
    * @param string $uri The object URI
    * 
    * @return array An array containing the result
    */
   public function getContactByUri($id, $uri)
   {
     $write = false;
     if(strpos($id, 'webdav://') === 0)
     {
         $wdc =& plugin_load('helper', 'webdavclient');
         if(is_null($wdc))
             return $this->getLang('no_wdc');
         $connectionId = str_replace('webdav://', '', $id);
         $settings = $wdc->getConnection($connectionId);
         
         if($settings === false)
             return array('formattedname' => $this->getLang('settings_not_found'), 'result' => false);
         if($settings['type'] !== 'contacts')
             return array('formattedname' => $this->getLang('wrong_type'), 'result' => false);
         
         $row = $wdc->getAddressbookEntryByUri($connectionId, $uri);
         $write = $settings['write'];
     }
     else
     {
         $acl = auth_quickaclcheck($id);
         if($acl > AUTH_READ)
         {
             $write = true;
         }
         elseif($acl < AUTH_READ)
         {
             return array('formattedname' => $this->getLang('no_permission'), 'result' => false);
         }
         else 
         {
             $write = false;
         }
         $addressbookid = $this->getAddressbookIdForPage($id);
         $row = $this->getAddressbookEntryByUri($addressbookid, $uri);       
     }
     
     if($row === false)
         return array('formattedname' => sprintf($this->getLang('contact_not_found'), 'ID='.$id.' URI='.$uri), 'result' => false);
     $info = $this->parseVcard($row['contactdata'], $row['uri'], $write);
     $info['result'] = true;
     return $info;
   }
   
   /**
    * Retrieve an address book entry by URI (low-level version)
    * 
    * @param int $id The address book ID
    * @param string $uri The object URI
    * 
    * @return array The contact's details
    */
   private function getAddressbookEntryByUri($id, $uri)
   {
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
       $query = "SELECT contactdata, addressbookid, etag, uri, formattedname, structuredname FROM addressbookobjects WHERE addressbookid = ? AND uri = ?";
-      $res = $this->sqlite->query($query, $id, $uri);
-      return $this->sqlite->res2row($res);
+      $res = $sqlite->query($query, $id, $uri);
+      return $sqlite->res2row($res);
   }
   
   /**
    * Set the addressbook name for a given page
    * 
    * @param string $name The name to set
    * @param string $description The address book description
    * @param int $id (optional) The page ID
    * @param string $userid (optional) The user's ID
    * 
    * @return boolean true on success, otherwise false 
    */
   public function setAddressbookNameForPage($name, $description, $id = null, $userid = null)
   {
       if(is_null($id))
       {
           global $ID;
           $id = $ID;
       }
       if(is_null($userid))
       {
         if(isset($_SERVER['REMOTE_USER']) && !is_null($_SERVER['REMOTE_USER']))
         {
           $userid = $_SERVER['REMOTE_USER'];
         }
         else
         {
           $userid = uniqid('davcard-');
         }
       }
       $bookid = $this->getAddressbookIdForPage($id);
       if($bookid === false)
         return $this->createAddressbookForPage($name, $description, $id, $userid);
       
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
       $query = "UPDATE addressbooks SET displayname = ?, description = ? WHERE id = ?";
-      $res = $this->sqlite->query($query, $name, $description, $bookid);
+      $res = $sqlite->query($query, $name, $description, $bookid);
       if($res !== false)
         return true;
       return false;
   }
   
   /**
    * Get the address book ID associated with a given page
    * 
    * @param string $id (optional) The page ID
    * 
    * @return mixed The address book ID or false
    */
   public function getAddressbookIdForPage($id = null)
   {
       if(is_null($id))
       {
           global $ID;
           $id = $ID;
       }
       
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
+      
       $query = "SELECT addressbookid FROM pagetoaddressbookmapping WHERE page = ?";
-      $res = $this->sqlite->query($query, $id);
-      $row = $this->sqlite->res2row($res);
+      $res = $sqlite->query($query, $id);
+      $row = $sqlite->res2row($res);
       if(isset($row['addressbookid']))
       {
         $addrbkid = $row['addressbookid'];
         return $addrbkid;
       }
       return false;
   }
   
   /**
    * Create a new address book for a given page
    * 
    * @param string $name The name of the new address book
    * @param string $description The address book's description
    * @param string $id (optional) The page ID
    * @param string $userid (optional) The user's ID
    * 
    * @return boolean True on success, otherwise false
    */
   public function createAddressbookForPage($name, $description, $id = null, $userid = null)
   {
       if(is_null($id))
       {
           global $ID;
           $id = $ID;
       }
       if(is_null($userid))
       {
         if(isset($_SERVER['REMOTE_USER']) && !is_null($_SERVER['REMOTE_USER']))
         {
           $userid = $_SERVER['REMOTE_USER'];
         }
         else
         {
           $userid = uniqid('davcard-');
         }
       }
+      
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
+      
       $values = array('principals/'.$userid, 
                       $name,
                       str_replace(array('/', ' ', ':'), '_', $id), 
                       $description,
                       1);
       $query = "INSERT INTO addressbooks (principaluri, displayname, uri, description, synctoken) ".
                "VALUES (?, ?, ?, ?, ?)";
-      $res = $this->sqlite->query($query, $values);
+      $res = $sqlite->query($query, $values);
       if($res === false)
         return false;
       
       // Get the new addressbook ID
       $query = "SELECT id FROM addressbooks WHERE principaluri = ? AND displayname = ? AND ".
                "uri = ? AND description = ? AND synctoken = ?";
-      $res = $this->sqlite->query($query, $values);
-      $row = $this->sqlite->res2row($res);
+      $res = $sqlite->query($query, $values);
+      $row = $sqlite->res2row($res);
       
       // Update the pagetocalendarmapping table with the new calendar ID
       if(isset($row['id']))
       {
           $query = "INSERT INTO pagetoaddressbookmapping (page, addressbookid) VALUES (?, ?)";
-          $res = $this->sqlite->query($query, $id, $row['id']);
+          $res = $sqlite->query($query, $id, $row['id']);
           return ($res !== false);
       }
       
       return false;
   }
 
   /**
    * Delete a contact entry from an address book by URI
    * 
    * @param string $id The address book ID
    * @param string $user The user's ID
    * @param string $uri The object URI to delete
    * 
    * @return boolean True on success, otherwise false
    */
   public function deleteContactEntryToAddressbookForPage($id, $user, $uri)
   {
       if(strpos($id, 'webdav://') === 0)
       {
         $wdc =& plugin_load('helper', 'webdavclient');
         if(is_null($wdc))
             return $this->getLang('no_wdc');
         $connectionId = str_replace('webdav://', '', $id);
         $settings = $wdc->getConnection($connectionId);
         
         if($settings === false)
             return array('formattedname' => $this->getLang('settings_not_found'), 'result' => false);
         if($settings['type'] !== 'contacts')
             return array('formattedname' => $this->getLang('wrong_type'), 'result' => false);
         
         return $wdc->deleteAddressbookEntry($connectionId, $uri);
       }
       
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
+      
       $addressbookid = $this->getAddressbookIdForPage($id);
       $query = "DELETE FROM addressbookobjects WHERE uri = ? AND addressbookid = ?";
       
-      $res = $this->sqlite->query($query, $uri, $addressbookid);
+      $res = $sqlite->query($query, $uri, $addressbookid);
       if($res !== false)
       {
           $this->updateSyncTokenLog($addressbookid, $uri, 'deleted');
           return true;
       }
       return false;
   }
 
   /**
    * Edit a contact for a given address book
    * 
    * @param string $id The address book ID
    * @param string $user The user name
    * @param string $uri The object URI
    * @param array $params The new address book parameters
    * 
    * @return boolean True on success, otherwise false
    */
   public function editContactEntryToAddressbookForPage($id, $user, $uri, $params)
   {
       require_once(DOKU_PLUGIN.'davcard/vendor/autoload.php');
       
       if(strpos($id, 'webdav://') === 0)
       {
         $wdc =& plugin_load('helper', 'webdavclient');
         if(is_null($wdc))
             return $this->getLang('no_wdc');
         $connectionId = str_replace('webdav://', '', $id);
         $settings = $wdc->getConnection($connectionId);
         
         if($settings === false)
             return array('formattedname' => $this->getLang('settings_not_found'), 'result' => false);
         if($settings['type'] !== 'contacts')
             return array('formattedname' => $this->getLang('wrong_type'), 'result' => false);
         
         $row = $wdc->getAddressbookEntryByUri($connectionId, $uri);
       }
       else
       {
         $addressbookid = $this->getAddressbookIdForPage($id);
         $row = $this->getAddressbookEntryByUri($addressbookid, $uri);       
       }
       $vcard = \Sabre\VObject\Reader::read($row['contactdata']);
       
       $vcard->remove('ADR');
       $vcard->remove('TEL');
       $vcard->remove('EMAIL');
       
       if(isset($params['phones']))
       {
           foreach($params['phones'] as $data)
           {
               $vcard->add('TEL', $data['number'], array('type' => $data['type']));
           }
       }
 
       if(isset($params['email']))
       {
           foreach($params['email'] as $data)
           {
               $vcard->add('EMAIL', $data['mail'], array('type' => $data['type']));
           }
       }
 
       if(isset($params['addresses']))
       {
           foreach($params['addresses'] as $data)
           {
               $vcard->add('ADR', array('', '', $data['street'], $data['city'], '', $data['zipcode'], $data['country']), array('type' => $data['type']));
           }
       }
       
       $structuredname = explode(';', (string)$vcard->N);
       $structuredname[0] = $params['lastname'];
       $structuredname[1] = $params['firstname'];
       $formattedname = $params['firstname'].' '.$params['lastname']; // FIXME: Make this configurable?
       $vcard->N = $structuredname;
       $vcard->FN = $formattedname;
       
       $contactdata = $vcard->serialize();
       
       if(strpos($id, 'webdav://') === 0)
       {
           return $wdc->editAddressbookEntry($connectionId, $uri, $contactdata);
       }
       else
       {
+          $sqlite = $this->getDB();
+          if(!$sqlite)
+            return false; 
           $now = new \DateTime();
           $query = "UPDATE addressbookobjects SET contactdata = ?, lastmodified = ?, etag = ?, size = ?, formattedname = ?, structuredname = ? WHERE addressbookid = ? AND uri = ?";
-          $res = $this->sqlite->query($query,
+          $res = $sqlite->query($query,
                                       $contactdata,
                                       $now->getTimestamp(),
                                       md5($contactdata),
                                       strlen($contactdata),
                                       $formattedname,
                                       implode(';', $structuredname),
                                       $addressbookid,
                                       $uri
                                       );
           if($res !== false)
           {
               $this->updateSyncTokenLog($addressbookid, $uri, 'modified');
               return true;
           }
       }
       return false;
   }
   
   /**
    * Add a new contact entry to an address book page
    * 
    * @param string $id The page ID
    * @param string $user The user ID
    * @param array $params The entry's parameters
    * 
    * @return boolean True on success, otherwise false
    */
   public function addContactEntryToAddressbookForPage($id, $user, $params)
   {
       require_once(DOKU_PLUGIN.'davcard/vendor/autoload.php');
       $vcard = new \Sabre\VObject\Component\VCard();
       $formattedname = $params['firstname'].' '.$params['lastname']; // FIXME: Make this configurable?
       $structuredname = array($params['lastname'], $params['firstname'], '', '', '');
       $vcard->FN =  $formattedname;
       $vcard->N = $structuredname;
 
       if(isset($params['phones']))
       {
         foreach($params['phones'] as $data)
         {
             $vcard->add('TEL', $data['number'], array('type' => $data['type']));
         }
       }
       if(isset($params['email']))
       {
           foreach($params['email'] as $data)
           {
               $vcard->add('EMAIL', $data['mail'], array('type' => $data['type']));
           }
       }
       if(isset($params['addresses']))
       {
           foreach($params['addresses'] as $data)
           {
               $vcard->add('ADR', array('', '', $data['street'], $data['city'], '', $data['zipcode'], $data['country']), array('type' => $data['type']));
           }
       }
 
       $contactdata = $vcard->serialize();
       
       if(strpos($id, 'webdav://') === 0)
       {
           $wdc =& plugin_load('helper', 'webdavclient');
           if(is_null($wdc))
             return false;
           $connectionId = str_replace('webdav://', '', $id);
           return $wdc->addAddressbookEntry($connectionId, $contactdata);
       }
       else
       {
+          $sqlite = $this->getDB();
+          if(!$sqlite)
+            return false; 
           $addressbookid = $this->getAddressbookIdForPage($id);
           $uri = uniqid('dokuwiki-').'.vcf';
           $now = new \DateTime();
           $query = "INSERT INTO addressbookobjects (contactdata, uri, addressbookid, lastmodified, etag, size, formattedname, structuredname) VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
-          $res = $this->sqlite->query($query, 
+          $res = $sqlite->query($query, 
                                       $contactdata, 
                                       $uri, 
                                       $addressbookid, 
                                       $now->getTimestamp(), 
                                       md5($contactdata), 
                                       strlen($contactdata), 
                                       $formattedname, 
                                       implode(';', $structuredname)
                                       );
           // If successfully, update the sync token database
           if($res !== false)
           {
               $this->updateSyncTokenLog($addressbookid, $uri, 'added');
               return true;
           }
       }
       return false;
   }
   
   /**
    * Parse a VCard and extract important contact information
    * 
    * @param string $card The VCard data
    * @param string $uri The object URI
    * @param boolean $write Writable
    * 
    * @return array An array with parsed data
    */
   public function parseVcard($card, $uri, $write)
   {
     require_once(DOKU_PLUGIN.'davcard/vendor/autoload.php');
       
     $vObject = \Sabre\VObject\Reader::read($card);
       
     $formattedname = '';
     $structuredname = '';
     $tel = array();
     $addr = array();
     $mail = array();
     $photo = array();
     $birthday = '';
     $note = '';
     $title = '';
     $url = '';
     
     if(isset($vObject->FN))
       $formattedname = (string)$vObject->FN;
     
     if(isset($vObject->N))
       $structuredname = join(';', $vObject->N->getParts());
     
     if(isset($vObject->TEL))
     {
         foreach($vObject->TEL as $number)
         {
             if(isset($number['TYPE']))
                 $tel[] = array('type' => strtolower((string)$number['TYPE']), 'number' => (string)$number);
             else
                 $tel[] = array('number' => (string)$number);
         }
     }
     
     if(isset($vObject->ADR))
     {
         foreach($vObject->ADR as $adr)
         {
             if(isset($adr['TYPE']))
                 $addr[] = array('type' => strtolower((string)$adr['TYPE']), 'address' => $adr->getParts());
             else
                 $addr[] = array('address' => $adr->getParts());
         }
     }
     
     if(isset($vObject->EMAIL))
     {
         foreach($vObject->EMAIL as $email)
         {
             if(isset($email['TYPE']))
                 $mail[] = array('type' => strtolower((string)$email['TYPE']), 'mail' => (string)$email);
             else
                 $mail[] = array('mail' => (string)$email);
         }
     }
     
     if(isset($vObject->PHOTO))
     {
         if(isset($vObject->PHOTO['TYPE']))
         {
             $photo[] = array('type' => strtolower((string)$vObject->PHOTO['TYPE']), 'photo' => (string)$vObject->PHOTO);
         }
         else
             $photo[] = array('photo' => (string)$vObject->PHOTO);
     }
     
     if(isset($vObject->BDAY))
     {
         $birthday = (string)$vObject->BDAY;
         $birthday = str_replace('-', '', $birthday);
     }
     
     if(isset($vObject->NOTE))
     {
         $note = (string)$vObject->NOTE;
     }
     
     if(isset($vObject->TITLE))
     {
         $title = (string)$vObject->TITLE;
     }
     
     if(isset($vObject->URL))
     {
         $url = (string)$vObject->URL;
     }
     
     return array(
         'formattedname' => $formattedname,
         'structuredname' => $structuredname,
         'tel' => $tel,
         'mail' => $mail,
         'addr' => $addr,
         'uri' => $uri,
         'photo' => $photo,
         'birthday' => $birthday,
         'note' => $note,
         'title' => $title,
         'url' => $url,
         'result' => true,
         'write' => $write
     );
   }
 
   /**
    * Retrieve the settings of a given address book
    * 
    * @param int $addressbookid The addressbook's ID
    * 
    * @return array The settings
    */
   public function getAddressbookSettings($addressbookid)
   {
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
       $query = "SELECT id, principaluri, displayname, uri, description, synctoken FROM addressbooks WHERE id= ? ";
-      $res = $this->sqlite->query($query, $addressbookid);
-      $row = $this->sqlite->res2row($res);
+      $res = $sqlite->query($query, $addressbookid);
+      $row = $sqlite->res2row($res);
       return $row;
   }
 
   /**
    * Retrieve the current synctoken for an address book
    * 
    * @param int $addressbookid The addressbook's ID
    * 
    * @return string The current synctoken
    */
   public function getSyncTokenForAddressbook($addressbookid)
   {
       $row = $this->getAddressbookSettings($addressbookid);
       if(isset($row['synctoken']))
           return $row['synctoken'];
       return false;
   }
   
   /**
    * Helper function to convert the operation name to 
    * an operation code as stored in the database
    * 
    * @param string $operationName The operation name
    * 
    * @return mixed The operation code or false
    */
   public function operationNameToOperation($operationName)
   {
       switch($operationName)
       {
           case 'added':
               return 1;
           break;
           case 'modified':
               return 2;
           break;
           case 'deleted':
               return 3;
           break;
       }
       return false;
   }
   
   /**
    * Update the synctoken log for a given address book
    * 
    * @param string $addressbookid The addressbook ID to work with
    * @param string $uri The object URI that was modified
    * @param string $operation The operation that was performed
    * 
    * @return boolean True on success, otherwise false
    */
   private function updateSyncTokenLog($addressbookid, $uri, $operation)
   {
       $currentToken = $this->getSyncTokenForAddressbook($addressbookid);
       $operationCode = $this->operationNameToOperation($operation);
       if(($operationCode === false) || ($currentToken === false))
           return false;
       $values = array($uri,
                       $currentToken,
                       $addressbookid,
                       $operationCode
       );
+      $sqlite = $this->getDB();
+      if(!$sqlite)
+        return false; 
       $query = "INSERT INTO addressbookchanges (uri, synctoken, addressbookid, operation) VALUES(?, ?, ?, ?)";
-      $res = $this->sqlite->query($query, $uri, $currentToken, $addressbookid, $operationCode);
+      $res = $sqlite->query($query, $uri, $currentToken, $addressbookid, $operationCode);
       if($res === false)
         return false;
       $currentToken++;
       $query = "UPDATE addressbooks SET synctoken = ? WHERE id = ?";
-      $res = $this->sqlite->query($query, $currentToken, $addressbookid);
+      $res = $sqlite->query($query, $currentToken, $addressbookid);
       return ($res !== false);
   }
  
 }
diff --git a/plugin.info.txt b/plugin.info.txt
--- a/plugin.info.txt
+++ b/plugin.info.txt
@@ -1,7 +1,7 @@
 base	davcard
 author  Andreas Boehler
 email   dev@aboehler.at
-date    2016-07-01
+date    2016-12-13
 name    Addressbook PlugIn with CardDAV client support
 desc    Show contact information from a CardDAV address book (needs webdavclient)
 url     http://www.dokuwiki.org/plugin:davcard