diff --git a/plugins/libkolab/lib/kolab_format_configuration.php b/plugins/libkolab/lib/kolab_format_configuration.php
index a099c59d..10c9eb90 100644
--- a/plugins/libkolab/lib/kolab_format_configuration.php
+++ b/plugins/libkolab/lib/kolab_format_configuration.php
@@ -1,107 +1,107 @@
 <?php
 
 /**
  * Kolab Configuration data model class
  *
  * @version @package_version@
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 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/>.
  */
 
 class kolab_format_configuration extends kolab_format
 {
     public $CTYPE = 'application/x-vnd.kolab.configuration';
 
     protected $xmltype = 'configuration';
 
     /**
      * Set properties to the kolabformat object
      *
      * @param array  Object data as hash array
      */
     public function set(&$object)
     {
         $this->init();
 
         if ($object['type'])
             $this->subtype = $object['type'];
 
         // adjust content-type string
         $this->CTYPE = 'application/x-vnd.kolab.configuration.' . $this->subtype;
 
         // cache this data
         $this->data = $this->kolab_object = $object;
         unset($this->data['_formatobj']);
     }
 
     /**
      *
      */
     public function is_valid()
     {
-        return $this->data || (is_object($this->obj) && $this->obj->isValid());
+        return !empty($this->data['uid']) && !empty($this->data['type']);
     }
 
     /**
      * Convert the Configuration object into a hash array data structure
      *
      * @return array  Config object data as hash array
      */
     public function to_array()
     {
         // load from XML if not done yet
         if (!empty($this->data))
             $this->init();
 
         // adjust content-type string
         if ($this->data['type']) {
             $this->subtype = $this->data;
             $this->CTYPE = 'application/x-vnd.kolab.configuration.' . $this->subtype;
         }
 
         return $this->data;
     }
 
     /**
      * Load data from old Kolab2 format
      */
     public function fromkolab2($record)
     {
         $object = array(
             'uid'     => $record['uid'],
             'changed' => $record['last-modification-date'],
         );
 
         $this->data = $object + $record;
     }
 
     /**
      * Callback for kolab_storage_cache to get object specific tags to cache
      *
      * @return array List of tags to save in cache
      */
     public function get_tags()
     {
         $tags = array();
 
         if ($this->data['type'] == 'dictionary')
             $tags = array($this->data['language']);
 
         return $tags;
     }
 
 }
diff --git a/plugins/libkolab/lib/kolab_format_contact.php b/plugins/libkolab/lib/kolab_format_contact.php
index cab7dedc..a7dcd5ce 100644
--- a/plugins/libkolab/lib/kolab_format_contact.php
+++ b/plugins/libkolab/lib/kolab_format_contact.php
@@ -1,338 +1,338 @@
 <?php
 
 /**
  * Kolab Contact model class
  *
  * @version @package_version@
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 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/>.
  */
 
 class kolab_format_contact extends kolab_format
 {
     public $CTYPE = 'application/x-vnd.kolab.contact';
 
     protected $xmltype = 'contact';
 
     public static $fulltext_cols = array('name', 'firstname', 'surname', 'middlename', 'email');
 
     public $phonetypes = array(
         'home'    => 'home1',
         'work'    => 'business1',
         'text'    => 'text',
         'main'    => 'primary',
         'homefax' => 'homefax',
         'workfax' => 'businessfax',
         'mobile'  => 'mobile',
         'isdn'    => 'isdn',
         'pager'   => 'pager',
         'car'     => 'car',
         'company' => 'company',
         'radio'   => 'radio',
         'telex'   => 'telex',
         'ttytdd'  => 'ttytdd',
         'other'   => 'other',
         'assistant' => 'assistant',
         'callback'  => 'callback',
     );
 
     public $addresstypes = array(
         'home' => 'home',
         'work' => 'business',
         'other' => 'other',
         'office' => 0,
     );
 
     // old Kolab 2 format field map
     private $kolab2_fieldmap = array(
       // kolab       => roundcube
       'full-name'    => 'name',
       'given-name'   => 'firstname',
       'middle-names' => 'middlename',
       'last-name'    => 'surname',
       'prefix'       => 'prefix',
       'suffix'       => 'suffix',
       'nick-name'    => 'nickname',
       'organization' => 'organization',
       'department'   => 'department',
       'job-title'    => 'jobtitle',
       'birthday'     => 'birthday',
       'anniversary'  => 'anniversary',
       'phone'        => 'phone',
       'im-address'   => 'im',
       'web-page'     => 'website',
       'profession'   => 'profession',
       'manager-name' => 'manager',
       'assistant'    => 'assistant',
       'spouse-name'  => 'spouse',
       'children'     => 'children',
       'body'         => 'notes',
       'pgp-publickey' => 'pgppublickey',
       'free-busy-url' => 'freebusyurl',
       'picture'       => 'photo',
     );
     private $kolab2_phonetypes = array(
         'home1' => 'home',
         'business1' => 'work',
         'business2' => 'work',
         'businessfax' => 'workfax',
     );
     private $kolab2_addresstypes = array(
         'business' => 'work'
     );
     private $kolab2_arrays = array(
         'web-page' => 'url',
         'im-address' => true,
         'manager-name' => true,
         'assistant' => true,
         'children' => true,
     );
     private $kolab2_gender = array(0 => 'male', 1 => 'female');
 
 
     /**
      * Default constructor
      */
     function __construct($xmldata = null, $subtype = null)
     {
         parent::__construct($xmldata, $subtype);
     }
 
     /**
      * Set contact properties to the kolabformat object
      *
      * @param array  Contact data as hash array
      */
     public function set(&$object)
     {
         $this->init();
 
         if ($object['uid'])
             $this->kolab_object['uid'] = $object['uid'];
 
         $this->kolab_object['last-modification-date'] = time();
 
         // map fields rcube => $kolab
         foreach ($this->kolab2_fieldmap as $kolab => $rcube) {
             $this->kolab_object[$kolab] = $object[$rcube];
         }
 
         // map gener values
         if (isset($object['gender'])) {
             $gender_map = array_flip($this->kolab2_gender);
             $this->kolab_object['gender'] = $gender_map[$object['gender']];
         }
 
         // format dates
         if ($object['birthday'] && ($date = @strtotime($object['birthday'])))
             $this->kolab_object['birthday'] = date('Y-m-d', $date);
         if ($object['anniversary'] && ($date = @strtotime($object['anniversary'])))
             $this->kolab_object['anniversary'] = date('Y-m-d', $date);
 
         // make sure these attributes are single string values
         foreach ($this->kolab2_arrays as $col => $field) {
             if (!is_array($this->kolab_object[$col]))
                 continue;
             if ($field === true) {
                 $values = $this->kolab_object[$col];
             }
             else {
                 $values = array();
                 foreach ($this->kolab_object[$col] as $v)
                     $values[] = $v[$field];
             }
             $this->kolab_object[$col] = join('; ', $values);
         }
 
         // save email addresses to field 'emails'
         $emails = array();
         foreach ((array)$object['email'] as $email)
             $emails[] = $email;
         $this->kolab_object['emails'] = join(', ', array_filter($emails));
         unset($this->kolab_object['email']);
 
         // map phone types
         foreach ((array)$this->kolab_object['phone'] as $i => $phone) {
             if ($type = $this->phonetypes[$phone['type']])
                 $this->kolab_object['phone'][$i]['type'] = $type;
         }
 
         // save addresses (how weird is that?!)
         $this->kolab_object['address'] = array();
         $seen_types = array();
         foreach ((array)$object['address'] as $adr) {
             if ($type = $this->addresstypes[$adr['type']]) {
                 $updated = false;
                 $basekey = 'addr-' . $type . '-';
 
                 $this->kolab_object[$basekey . 'type']     = $type;
                 $this->kolab_object[$basekey . 'street']   = $adr['street'];
                 $this->kolab_object[$basekey . 'locality'] = $adr['locality'];
                 $this->kolab_object[$basekey . 'postal-code'] = $adr['zipcode'];
                 $this->kolab_object[$basekey . 'region']   = $adr['region'];
                 $this->kolab_object[$basekey . 'country']  = $adr['country'];
 
                 // check if we updates an existing address entry of this type...
                 foreach($this->kolab_object['address'] as $index => $address) {
                     if ($this->kolab_object['type'] == $type) {
                         $this->kolab_object['address'][$index] = $new_address;
                         $updated = true;
                     }
                 }
 
                 // ... add as new if not
                 if (!$updated) {
                     $this->kolab_object['address'][] = array(
                         'type'     => $type,
                         'street'   => $adr['street'],
                         'locality' => $adr['locality'],
                         'postal-code' => $adr['code'],
                         'region'   => $adr['region'],
                         'country'  => $adr['country'],
                     );
                 }
 
                 $seen_types[$type] = true;
             }
             else if ($adr['type'] == 'office') {
                 $this->kolab_object['office-location'] = $adr['locality'];
             }
         }
 
         // unset removed address properties
         foreach ($this->addresstypes as $type) {
             if (!$seen_types[$type]) {
                 $basekey = 'addr-' . $type . '-';
                 unset(
                     $this->kolab_object[$basekey . 'type'],
                     $this->kolab_object[$basekey . 'street'],
                     $this->kolab_object[$basekey . 'locality'],
                     $this->kolab_object[$basekey . 'postal-code'],
                     $this->kolab_object[$basekey . 'region'],
                     $this->kolab_object[$basekey . 'country']
                 );
             }
         }
 
         // cache this data
         $this->data = $object;
         unset($this->data['_formatobj']);
     }
 
     /**
      *
      */
     public function is_valid()
     {
-        return strlen($this->data['uid']);
+        return !empty($this->data['uid']);
     }
 
     /**
      * Callback for kolab_storage_cache to get words to index for fulltext search
      *
      * @return array List of words to save in cache
      */
     public function get_words()
     {
         $data = '';
         foreach (self::$fulltext_cols as $col) {
             $val = is_array($this->data[$col]) ? join(' ', $this->data[$col]) : $this->data[$col];
             if (strlen($val))
                 $data .= $val . ' ';
         }
 
         return array_unique(rcube_utils::normalize_string($data, true));
     }
 
     /**
      * Load data from old Kolab2 format
      *
      * @param array Hash array with object properties
      */
     public function fromkolab2($record)
     {
         $object = array(
           'uid' => $record['uid'],
           'changed' => $record['last-modification-date'],
           'email' => array(),
           'phone' => array(),
         );
 
         foreach ($this->kolab2_fieldmap as $kolab => $rcube) {
             if (is_array($record[$kolab]) || strlen($record[$kolab])) {
                 $object[$rcube] = $record[$kolab];
 
                 // split pseudo-arry values
                 if ($field = $this->kolab2_arrays[$kolab]) {
                     if ($field === true) {
                         $object[$rcube] = explode('; ', $record[$kolab]);
                     }
                     else {
                         $values = array();
                         foreach (explode('; ', $record[$kolab]) as $v)
                             $values[] = array($field => $v);
                         $object[$rcube] = $values;
                     }
                 }
             }
         }
 
         if (isset($record['gender']))
             $object['gender'] = $this->kolab2_gender[$record['gender']];
 
         foreach ((array)$record['email'] as $i => $email)
             $object['email'][] = $email['smtp-address'];
 
         if (!$record['email'] && $record['emails'])
             $object['email'] = preg_split('/,\s*/', $record['emails']);
 
         if (is_array($record['address'])) {
             $kolab2_addresstypes = array_flip($this->addresstypes);
             foreach ($record['address'] as $i => $adr) {
                 $object['address'][] = array(
                     'type' => $kolab2_addresstypes[$adr['type']] ? $kolab2_addresstypes[$adr['type']] : $adr['type'],
                     'street' => $adr['street'],
                     'locality' => $adr['locality'],
                     'code' => $adr['postal-code'],
                     'region' => $adr['region'],
                     'country' => $adr['country'],
                 );
             }
         }
 
         // map Kolab format phone types to Roundcube types
         if (!empty($object['phone'])) {
             $kolab2_phonetypes = array_merge(array_flip($this->phonetypes), $this->kolab2_phonetypes);
             foreach ($object['phone'] as $i => $phone) {
                 if ($type = $kolab2_phonetypes[$phone['type']])
                     $object['phone'][$i]['type'] = $type;
             }
         }
 
         // office location goes into an address block
         if ($record['office-location'])
             $object['address'][] = array('type' => 'office', 'locality' => $record['office-location']);
 
         // merge initials into nickname
         if ($record['initials'])
             $object['nickname'] = trim($object['nickname'] . ', ' . $record['initials'], ', ');
 
         // remove empty fields
         $this->data = array_filter($object);
     }
 
 }
diff --git a/plugins/libkolab/lib/kolab_format_distributionlist.php b/plugins/libkolab/lib/kolab_format_distributionlist.php
index b6fc5664..67822dfd 100644
--- a/plugins/libkolab/lib/kolab_format_distributionlist.php
+++ b/plugins/libkolab/lib/kolab_format_distributionlist.php
@@ -1,92 +1,92 @@
 <?php
 
 /**
  * Kolab Distribution List model class
  *
  * @version @package_version@
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 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/>.
  */
 
 class kolab_format_distributionlist extends kolab_format
 {
     public $CTYPE = 'application/x-vnd.kolab.distribution-list';
 
     protected $xmltype = 'distributionlist';
 
 
     /**
      * Set properties to the kolabformat object
      *
      * @param array  Object data as hash array
      */
     public function set(&$object)
     {
         $this->init();
 
         if ($object['uid'])
             $this->kolab_object['uid'] = $object['uid'];
 
         $this->kolab_object['last-modification-date'] = time();
         $this->kolab_object['last-name'] = $object['name'];
         $this->kolab_object['member'] = array();
 
         foreach ($object['member'] as $member) {
             $this->kolab_object['member'][] = array(
                 'uid' => $member['uid'],
                 'smtp-address' => $member['email'],
                 'display-name' => $member['name'],
             );
         }
 
         // set type property for proper caching
         $object['_type'] = 'distribution-list';
 
         // cache this data
         $this->data = $object;
         unset($this->data['_formatobj']);
     }
 
     public function is_valid()
     {
-        return !empty($this->data['uid']);
+        return !empty($this->data['uid']) && !empty($this->data['name']);
     }
 
     /**
      * Load data from old Kolab2 format
      */
     public function fromkolab2($record)
     {
         $object = array(
             'uid'     => $record['uid'],
             'changed' => $record['last-modification-date'],
             'name'    => $record['last-name'],
             'member'  => array(),
         );
 
         foreach ((array)$record['member'] as $member) {
             $object['member'][] = array(
                 'email' => $member['smtp-address'],
                 'name' => $member['display-name'],
                 'uid' => $member['uid'],
             );
         }
 
         $this->data = $object;
     }
 
 }