Redirection problem.Please help

[BaHyXuH]

When my users try to log in there is a message shown as always in vbulletin-Login successful u will be redirected.After this message they are back to the index but NOT LOGGED.I have changed this log in/redirection template for something but i dont know which is this template and how to fix it.
P.S
I used some vb hack to make people be redirected directly to the previously post instead to the index page and i may have done sth wrong and i thing the problems comes from this.Could u please tell me how to fix it? ;]
10x anyway {}

--------------- Added [DATE]1196190261[/DATE] at [TIME]1196190261[/TIME] ---------------

Please help me out.My members cannot login...;(