fixed bug, see http://www.howtoforge.com/forums/showthread.php?p=298953

mrtnzlml

2013-07-26 aebc94e92488fa3ecaaebe713560b65986a271d4

1
ALTER TABLE  `sys_session` CHANGE  `session_id`  `session_id` VARCHAR( 64 ) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL;