diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index 1937ec4751..bd9205d410 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -640,7 +640,7 @@ class calendar_boupdate extends calendar_bo
 		$version = $GLOBALS['egw_info']['apps']['calendar']['version'];
 
 		// ignore events in the past (give a tolerance of 10 seconds for the script)
-		if($old_event != False && $this->date2ts($old_event['start']) < ($this->now_su - 10))
+		if($old_event && $this->date2ts($old_event['start']) < ($this->now_su - 10))
 		{
 			return False;
 		}
@@ -745,7 +745,7 @@ class calendar_boupdate extends calendar_bo
 		$startdate = new egw_time($event['start']);
 		$enddate = new egw_time($event['end']);
 		$modified = new egw_time($event['modified']);
-		if ($old_event != False) $olddate = new egw_time($old_event['start']);
+		if ($old_event) $olddate = new egw_time($old_event['start']);
 		foreach($to_notify as $userid => $statusid)
 		{
 			unset($res_info);
@@ -762,7 +762,7 @@ class calendar_boupdate extends calendar_bo
 					// check if event-owner wants non-EGroupware users notified
 					if (is_null($owner_prefs))
 					{
-						$preferences = new preferences($old_event['owner']);
+						$preferences = new preferences($owner);
 						$owner_prefs = $preferences->read_repository();
 					}
 					if ($role != 'CHAIR' &&		// always notify externals CHAIRs
@@ -797,7 +797,7 @@ class calendar_boupdate extends calendar_bo
 				{
 					if (is_null($owner_prefs))
 					{
-						$preferences = new preferences($old_event['owner']);
+						$preferences = new preferences($owner);
 						$GLOBALS['egw_info']['user']['preferences'] = $owner_prefs = $preferences->read_repository();
 					}
 					$part_prefs = $owner_prefs;
diff --git a/calendar/inc/class.calendar_uilist.inc.php b/calendar/inc/class.calendar_uilist.inc.php
index dd071064c1..ef52376911 100644
--- a/calendar/inc/class.calendar_uilist.inc.php
+++ b/calendar/inc/class.calendar_uilist.inc.php
@@ -5,7 +5,7 @@
  * @link http://www.egroupware.org
  * @package calendar
  * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
- * @copyright (c) 2005-11 by RalfBecker-At-outdoor-training.de
+ * @copyright (c) 2005-12 by RalfBecker-At-outdoor-training.de
  * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
  * @version $Id$
  */
@@ -247,14 +247,17 @@ class calendar_uilist extends calendar_ui
 			}
 		}
 		$old_params = egw_session::appsession('calendar_list','calendar');
-		if ($old_params['filter'] && $old_params['filter'] != $params['filter'])	// filter changed => order accordingly
+		if (is_array($old_params))
 		{
-			$params['order'] = 'cal_start';
-			$params['sort'] = $params['filter'] == 'after' ? 'ASC' : 'DESC';
-		}
-		if ($old_params['search'] != $params['search'])
-		{
-			$this->adjust_for_search($params['search'],$params);
+			if ($old_params['filter'] && $old_params['filter'] != $params['filter'])	// filter changed => order accordingly
+			{
+				$params['order'] = 'cal_start';
+				$params['sort'] = $params['filter'] == 'after' ? 'ASC' : 'DESC';
+			}
+			if ($old_params['search'] != $params['search'])
+			{
+				$this->adjust_for_search($params['search'],$params);
+			}
 		}
 		if (!$params['csv_export']) egw_session::appsession('calendar_list','calendar',$params);