After upgrade to the version 4.02 PL4 vBulletin I had problems with registration new users. After the registration, user immediately is shown as login and all seems to be good. Problem appears after logging out - at the second time you cannot log in. Entered datas are recognized as incorrect. Similar problem appears with users accounts set up by Administrator from the level of ACP. Described problem does not apply only to old accounts. Did someone know solution of this problem?