diff --git a/phpgwapi/inc/class.sessions_php4.inc.php b/phpgwapi/inc/class.sessions_php4.inc.php
index ba2e53b86a..237118529b 100644
--- a/phpgwapi/inc/class.sessions_php4.inc.php
+++ b/phpgwapi/inc/class.sessions_php4.inc.php
@@ -181,16 +181,17 @@
 			) * $sign;
 		}
 
-		/*!
-		@function list_sessions
-		@abstract get list of normal / non-anonymous sessions
-		@note The data form the session-files get cached in the app_session phpgwapi/php4_session_cache
-		@author ralfbecker
-		*/
+		/**
+		 * get list of normal / non-anonymous sessions (works only for session.handler = files!, but that's the default)
+		 *
+		 * The data from the session-files get cached in the app_session phpgwapi/php4_session_cache
+		 *
+		 * @author RalfBecker-AT-outdoor-training.de
+		 */
 		function list_sessions($start,$order,$sort,$all_no_sort = False)
 		{
 			//echo "<p>session_php4::list_sessions($start,'$order','$sort',$all)</p>\n";
-			//$session_cache = $this->appsession('php4_session_cache','phpgwapi');
+			$session_cache = $this->appsession('php4_session_cache','phpgwapi');
 
 			$values = array();
 			$maxmatchs = $GLOBALS['egw_info']['user']['preferences']['common']['maxmatchs'];
@@ -199,19 +200,25 @@
 			{
 				return $values;
 			}
-			while ($file = readdir($dir))
+			while (($file = readdir($dir)))
 			{
 				if (substr($file,0,5) != 'sess_' || $session_cache[$file] === false)
 				{
 					continue;
 				}
+				if (isset($session_cache[$file]) && !$session_cache[$file])		// session is marked as not to list (not ours or anonymous)
+				{
+					continue;
+				}
 				if (isset($session_cache[$file]))	// use copy from cache
 				{
-					if (!$all_no_sort)	// we need the up-to-date data --> unset and reread it
+					$session = $session_cache[$file];
+
+					if (!$all_no_sort || 			// we need the up-to-date data --> unset and reread it
+						$session['session_dla'] <= (time() - $GLOBALS['egw_info']['server']['sessions_timeout']))	// cached dla is timeout
 					{
 						unset($session_cache[$file]);
 					}
-					$session = $session_cache[$file];
 				}
 				if (!isset($session_cache[$file]))	// not in cache, read and cache it
 				{
@@ -234,16 +241,25 @@
 					$session = unserialize(substr($session,1+strlen(EGW_SESSION_VAR)));
 					unset($session['app_sessions']);	// not needed, saves memory
 					$session_cache[$file] = $session;
-				}
-				if($session['session_flags'] == 'A' || !$session['session_id'] ||
-					$session['session_install_id'] != $GLOBALS['egw_info']['server']['install_id'])
-				{
-					$session_cache[$file] = false;	// dont try reading it again
-					continue;	// no anonymous sessions or other domains or installations
+
+					if($session['session_flags'] == 'A' || !$session['session_id'] ||
+						$session['session_install_id'] != $GLOBALS['egw_info']['server']['install_id'])
+					{
+						$session_cache[$file] = false;	// dont try reading it again
+						continue;	// no anonymous sessions or other domains or installations
+					}
+					// check for and terminate sessions which are timed out ==> destroy them
+					// this should be not necessary if php is configured right, but I'm sick of the questions on the list
+					if ($session['session_dla'] <= (time() - $GLOBALS['egw_info']['server']['sessions_timeout']))
+					{
+						//echo "session $session[session_id] is timed out !!!<br>\n";
+						@unlink($path . '/' . $file);
+						$session_cache[$file] = false;
+						continue;
+					}
+					$session['php_session_file'] = $path . '/' . $file;
 				}
 				//echo "file='$file'=<pre>"; print_r($session); echo "</pre>"; 
-
-				$session['php_session_file'] = $path . '/' . $file;
 				$values[$session['session_id']] = $session;
 			}
 			closedir($dir);
@@ -272,11 +288,11 @@
 			return $values;
 		}
 
-		/*!
-		@function total
-		@abstract get number of normal / non-anonymous sessions
-		@author ralfbecker
-		*/
+		/**
+		 * get number of normal / non-anonymous sessions
+		 *
+		 * @author RalfBecker-AT-outdoor-training.de
+		 */
 		function total()
 		{
 			return count($this->list_sessions(0,'','',True));