diff --git a/plugins/libkolab/lib/kolab_storage_cache.php b/plugins/libkolab/lib/kolab_storage_cache.php
index 4c822f6e..be94bb87 100644
--- a/plugins/libkolab/lib/kolab_storage_cache.php
+++ b/plugins/libkolab/lib/kolab_storage_cache.php
@@ -29,6 +29,7 @@ class kolab_storage_cache
     private $folder;
     private $uid2msg;
     private $objects;
+    private $index = array();
     private $resource_uri;
     private $enabled = true;
     private $synched = false;
@@ -422,7 +423,7 @@ class kolab_storage_cache
     private function _serialize($object)
     {
         $bincols = array_flip($this->binary_cols);
-        $sql_data = array('dtstart' => null, 'dtend' => null, 'xml' => '');
+        $sql_data = array('dtstart' => null, 'dtend' => null, 'xml' => '', 'tags' => '', 'words' => '');
 
         // set type specific values
         if ($this->folder->type == 'event') {
diff --git a/plugins/libkolab/lib/kolab_storage_folder.php b/plugins/libkolab/lib/kolab_storage_folder.php
index 7ae1a1eb..6c4b4010 100644
--- a/plugins/libkolab/lib/kolab_storage_folder.php
+++ b/plugins/libkolab/lib/kolab_storage_folder.php
@@ -271,7 +271,8 @@ class kolab_storage_folder
     {
         if (!$type) $type = $this->type;
 
-        // TODO: synchronize cache first?
+        // synchronize cache first
+        $this->cache->synchronize();
 
         return $this->cache->count(array(array('type','=',$type)));
     }
@@ -625,6 +626,7 @@ class kolab_storage_folder
         $format->set($object);
         $xml = $format->write();
         $object['uid'] = $format->uid;  // get read UID from format
+        $object['_formatobj'] = $format;
 
         if (!$format->is_valid() || empty($object['uid'])) {
             return false;