SQL error in do_update(): INSERT INTO tbl_ws_session ( session_id, time_created, time_expires ) VALUES ( '8034ca9a21069bd4dcd4e4e858b32091','2010-09-10 15:20:20','2010-09-10 17:20:20'): Duplicate entry '8034ca9a21069bd4dcd4e4e858b32091' for key 1