diff --git a/plugins/kolab_addressbook/rcube_kolab_contacts.php b/plugins/kolab_addressbook/rcube_kolab_contacts.php
index 2774cd65..af3daa8d 100644
--- a/plugins/kolab_addressbook/rcube_kolab_contacts.php
+++ b/plugins/kolab_addressbook/rcube_kolab_contacts.php
@@ -130,7 +130,9 @@ class rcube_kolab_contacts extends rcube_addressbook
      */
     public function get_name()
     {
-        return strtr(preg_replace('!^(INBOX|user)/!i', '', $this->imap_folder), '/', ':');
+        $folder = rcube_charset_convert($this->imap_folder, 'UTF7-IMAP');
+        // @TODO: use namespace prefixes
+        return strtr(preg_replace('!^(INBOX|user)/!i', '', $folder), '/', ':');
     }
 
 
diff --git a/plugins/kolab_core/README.txt b/plugins/kolab_core/README.txt
index 89c64a60..3b82e898 100644
--- a/plugins/kolab_core/README.txt
+++ b/plugins/kolab_core/README.txt
@@ -20,6 +20,7 @@ pear install Net_DNS2
 pear install Net_SMTP
 pear install Mail_mimeDecode
 pear install Auth_SASL
+pear install Date
 
 
 Configuration
diff --git a/plugins/kolab_core/rcube_kolab.php b/plugins/kolab_core/rcube_kolab.php
index d800d773..92ec41fa 100644
--- a/plugins/kolab_core/rcube_kolab.php
+++ b/plugins/kolab_core/rcube_kolab.php
@@ -87,7 +87,7 @@ class rcube_kolab
      * Get a list of storage folders for the given data type
      *
      * @param string Data type to list folders for (contact,event,task,note)
-     * @return array List of Kolab_Folder objects
+     * @return array List of Kolab_Folder objects (folder names in UTF7-IMAP)
      */
     public static function get_folders($type)
     {
@@ -99,7 +99,7 @@ class rcube_kolab
     /**
      * Get storage object for read/write access to the Kolab backend
      *
-     * @param string IMAP folder to access
+     * @param string IMAP folder to access (UTF7-IMAP)
      * @param string Object type to deal with (leave empty for auto-detection using annotations)
      * @return object Kolab_Data The data storage object
      */
@@ -122,10 +122,13 @@ class rcube_kolab
 
     /**
      * Creates folder ID from folder name
+     *
+     * @param string $folder Folder name (UTF7-IMAP)
+     *
+     * @return string Folder ID string
      */
     public static function folder_id($folder)
     {
-        $folder = rcube_charset_convert($folder, RCMAIL_CHARSET, 'UTF7-IMAP');
         return asciiwords(strtr($folder, '/.', '--'));
     }