one could only presume that it would be found either in the main registration template (highly unlikely) or in register.php (the main registration file) . . . try getting the link and then do a search for the link in the form of
Code:
$vboptions[forumhome].php?$session[sessionurl]
that should be the exact code u need to look for (as I just looked it up) . . . hope this helps, peace out
that bit of code stands for the index.php file of your forums page, along with the users current session. . . therefore, if u find that code, and make the change to, lets say, "../index.php" . . . then that should do it