--- horde-orig/lib/Horde/SessionHandler/mysql.php	2010-04-29 06:58:43.000000000 -0400
+++ horde/lib/Horde/SessionHandler/mysql.php	2010-08-09 15:23:16.095086203 -0400
@@ -125,8 +125,11 @@
 
         if (!empty($this->_params['rowlocking'])) {
             /* Start a transaction. */
-            $result = @mysql_query('START TRANSACTION', $this->_db);
-            $query .= ' FOR UPDATE';
+            $result = @mysql_query('SET TRANSACTION ISOLATION LEVEL READ COMMITTED;', $this->_db);
+            if($result) {
+                $result = @mysql_query('START TRANSACTION', $this->_db);
+                $query .= ' FOR UPDATE';
+            }
         } else {
             $result = @mysql_query('LOCK TABLES ' . $this->_params['table'] . ' WRITE', $this->_db);
         }