What version is installed? This problem has come up a couple times before, and I thought it was fixed in the latest .75 version, at least.
If you’re not using .75, I would start there. Here are some forum posts that dealt with the redirect issue before .75 came out:
https://bbpress.org/forums/topic/531?replies=20#post-3050
I just installed today, so it should be the latest version. but i’ll try what they r saying in the other post.
DonHarry
go to config.php
add this $bb->debug = 1;
and then let us know.. we’ll try to debug this problem..
did it, but even with the given informations I can’t solve the problem. think it is one of my filled in data.
DonHarry – what was the debug information? Maybe someone else can help? I see your server is Apache 2.2.3 and the PHP version is 5.2.0. I don’t think any of the earlier solutions will apply, especially if you are using the latest 0.75 version.
Maybe you can post your config.php with the tasty portions replaced with xxx (be careful not to change any quotations, slashes or semicolons). Maybe you have a problem there.
the problem is your config.php
it should be
$bb->domain = 'http://videos.superheldenclub.de';
$bb->path = '/community/';
and not
$bb->domain = 'http://videos.superheldenclub.de/community';
$bb->path = '/';
thank you guys! I knew there was something wrong with my details, but I didn’t catch it – my fault, should have read everything more specificly. thank you very much! 
now it works, but there is another problem while trying to edit the profile
Warning: require(profile-edit.php) [function.require]: failed to open stream: No such file or directory in /www/htdocs/w0056475/superheldenclub/videos/community/profile.php on line 20
Fatal error: require() [function.require]: Failed opening required ‘profile-edit.php’ (include_path=’.:/usr/share/php:..’) in /www/htdocs/w0056475/superheldenclub/videos/community/profile.php on line 20
just like it says.. you are missing your profile-edit.php
