Index: trunk/kernel/units/general/inp_ses_storage.php
===================================================================
diff -u -r3887 -r4758
--- trunk/kernel/units/general/inp_ses_storage.php	(.../inp_ses_storage.php)	(revision 3887)
+++ trunk/kernel/units/general/inp_ses_storage.php	(.../inp_ses_storage.php)	(revision 4758)
@@ -54,19 +54,20 @@
 
 	function LocateSession($sid)
 	{
-		$query = ' SELECT '.$this->TimestampField.' FROM '.$this->TableName.' WHERE '.$this->IDField.' = '.$this->Conn->qstr($sid);
-		$result = $this->Conn->GetOne($query);
-
-		if($result===false) return false;
-
-		$this->Expiration = $result + $this->SessionTimeout;
-		return true;
+		$res = parent::LocateSession($sid);
+		if ($res) {
+			$this->Expiration +=  $this->SessionTimeout;
+		}
+		return $res;
 	}
 
 	function UpdateSession(&$session)
 	{
-		$query = ' UPDATE '.$this->TableName.' SET '.$this->TimestampField.' = unix_timestamp() WHERE '.$this->IDField.' = '.$this->Conn->qstr($session->SID);
-		$this->Conn->Query($query);
+		$time = adodb_mktime();
+		// Update LastAccessed only if it's newer than 1/10 of session timeout - perfomance optimization to eliminate needless updates on every click
+		if ($time - $this->DirectVars['LastAccessed'] > $this->SessionTimeout/10) {
+			$this->SetField($session, $this->TimestampField, $time);
+		}
 	}
 
 
@@ -78,15 +79,15 @@
 								'IpAddress'		=>	$_SERVER['REMOTE_ADDR'],
 								'GroupList'		=>	$this->Application->ConfigValue('User_GuestGroup'),
 								'CurrentTempKey'=>	$session->SID,
-								
+
 						);
-		
+
 		parent::StoreSession($session, $fields_hash);
 	}
 
 	function GetExpiredSIDs()
 	{
-		$query = ' SELECT '.$this->IDField.' FROM '.$this->TableName.' WHERE '.adodb_mktime().' - '.$this->TimestampField.' > '.$this->SessionTimeout;
+		$query = ' SELECT '.$this->IDField.' FROM '.$this->TableName.' WHERE  '.$this->TimestampField.' < '.(adodb_mktime()-$this->SessionTimeout);
 		$ret = $this->Conn->GetCol($query);
 		if($ret) {
 			$this->DeleteEditTables();