Please Help!!!!

[FRANKTHETANK 2]

I THINK I GOT HACKED. my homepage still works. but when i go to forums i get nothen but this error page. please help i don't know what to do.

address - http://www.315riders.com

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@315riders.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache/2.0.63 (Unix) mod_ssl/2.0.63 OpenSSL/0.9.7a mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 Server at www.315riders.com Port 80

also my other site i have hosted in same account works fine.

--------------- Added [DATE]1244873500[/DATE] at [TIME]1244873500[/TIME] ---------------

now my site is back up. but it was like this for about 1/2 hour, what caused this do you guys think?