diff --git a/lib/kolab_sync_backend_content.php b/lib/kolab_sync_backend_content.php
index 36432cb..0944613 100644
--- a/lib/kolab_sync_backend_content.php
+++ b/lib/kolab_sync_backend_content.php
@@ -1,138 +1,137 @@
 <?php
 
 /**
  +--------------------------------------------------------------------------+
  | Kolab Sync (ActiveSync for Kolab)                                        |
  |                                                                          |
  | Copyright (C) 2011-2012, Kolab Systems AG <contact@kolabsys.com>         |
  |                                                                          |
  | This program is free software: you can redistribute it and/or modify     |
  | it under the terms of the GNU Affero General Public License as published |
  | by the Free Software Foundation, either version 3 of the License, or     |
  | (at your option) any later version.                                      |
  |                                                                          |
  | This program is distributed in the hope that it will be useful,          |
  | but WITHOUT ANY WARRANTY; without even the implied warranty of           |
  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the             |
  | GNU Affero General Public License for more details.                      |
  |                                                                          |
  | You should have received a copy of the GNU Affero General Public License |
  | along with this program. If not, see <http://www.gnu.org/licenses/>      |
  +--------------------------------------------------------------------------+
  | Author: Aleksander Machniak <machniak@kolabsys.com>                      |
  +--------------------------------------------------------------------------+
 */
 
 /**
  * Kolab backend class for content storage
  */
 class kolab_sync_backend_content extends kolab_sync_backend_common implements Syncroton_Backend_IContent
 {
     protected $table_name     = 'syncroton_content';
     protected $interface_name = 'Syncroton_Model_IContent';
 
 
     /**
      * mark state as deleted. The state gets removed finally,
      * when the synckey gets validated during next sync.
      *
      * @param Syncroton_Model_IContent|string $id
      */
     public function delete($id)
     {
         $id = $id instanceof Syncroton_Model_IContent ? $id->id : $id;
 
         $result = $this->db->query("UPDATE `{$this->table_name}` SET `is_deleted` = 1 WHERE `id` = ?", array($id));
 
         if ($result = (bool) $this->db->affected_rows($result)) {
             unset($this->cache['content_folderstate']);
         }
 
         return $result;
     }
 
     /**
      * @param Syncroton_Model_IDevice|string $_deviceId
      * @param Syncroton_Model_IFolder|string $_folderId
      * @param string $_contentId
      *
      * @return Syncroton_Model_IContent
      */
     public function getContentState($_deviceId, $_folderId, $_contentId)
     {
         $deviceId = $_deviceId instanceof Syncroton_Model_IDevice ? $_deviceId->id : $_deviceId;
         $folderId = $_folderId instanceof Syncroton_Model_IFolder ? $_folderId->id : $_folderId;
 
         $where[] = $this->db->quote_identifier('device_id') . ' = ' . $this->db->quote($deviceId);
         $where[] = $this->db->quote_identifier('folder_id') . ' = ' . $this->db->quote($folderId);
         $where[] = $this->db->quote_identifier('contentid') . ' = ' . $this->db->quote($_contentId);
         $where[] = $this->db->quote_identifier('is_deleted') . ' = 0';
 
         $select = $this->db->query("SELECT * FROM `{$this->table_name}` WHERE " . implode(' AND ', $where));
         $state  = $this->db->fetch_assoc($select);
 
         if (empty($state)) {
             throw new Syncroton_Exception_NotFound('Content not found');
         }
 
         return $this->get_object($state);
     }
 
     /**
      * get array of ids which got send to the client for a given class
      *
      * @param Syncroton_Model_IDevice|string $_deviceId
      * @param Syncroton_Model_IFolder|string $_folderId
      * @param int                            $syncKey
      *
      * @return array
      */
     public function getFolderState($_deviceId, $_folderId, $syncKey = null)
     {
         $deviceId = $_deviceId instanceof Syncroton_Model_IDevice ? $_deviceId->id : $_deviceId;
         $folderId = $_folderId instanceof Syncroton_Model_IFolder ? $_folderId->id : $_folderId;
         $cachekey = $deviceId . ':' . $folderId . ':' . ($syncKey ?: '*');
 
         // in Sync request we call this function twice in case when
         // folder state changed - use cache to skip at least one SELECT query
         if (isset($this->cache['content_folderstate'][$cachekey])) {
             return $this->cache['content_folderstate'][$cachekey];
         }
 
         $where[] = $this->db->quote_identifier('device_id') . ' = ' . $this->db->quote($deviceId);
         $where[] = $this->db->quote_identifier('folder_id') . ' = ' . $this->db->quote($folderId);
         $where[] = $this->db->quote_identifier('is_deleted') . ' = 0';
         if ($syncKey) {
             $where[] = $this->db->quote_identifier('creation_synckey') . ' < ' . $this->db->quote($syncKey + 1);
         }
 
         $select = $this->db->query("SELECT `contentid` FROM `{$this->table_name}` WHERE " . implode(' AND ', $where));
         $result = array();
 
         while ($state = $this->db->fetch_assoc($select)) {
             $result[] = $state['contentid'];
         }
 
         return $this->cache['content_folderstate'][$cachekey] = $result;
     }
 
     /**
      * reset list of stored id
      *
      * @param Syncroton_Model_IDevice|string $_deviceId
      * @param Syncroton_Model_IFolder|string $_folderId
      */
     public function resetState($_deviceId, $_folderId)
     {
         $deviceId = $_deviceId instanceof Syncroton_Model_IDevice ? $_deviceId->id : $_deviceId;
         $folderId = $_folderId instanceof Syncroton_Model_IFolder ? $_folderId->id : $_folderId;
-        $cachekey = $deviceId . ':' . $folderId;
 
-        unset($this->cache['content_folderstate'][$cachekey]);
+        unset($this->cache['content_folderstate']);
 
         $where[] = $this->db->quote_identifier('device_id') . ' = ' . $this->db->quote($deviceId);
         $where[] = $this->db->quote_identifier('folder_id') . ' = ' . $this->db->quote($folderId);
 
         $this->db->query("DELETE FROM `{$this->table_name}` WHERE " . implode(' AND ', $where));
     }
 }