[wtfaatp]

Okay start out like this...

Go to you admin cP.
Go to settings.
Click on the drop down.
Select 'Site Name / URL / Contact Details'

Now look for 'Forum URL'
Make sure that is the absolute URL path (In your case do http://urwebsite.com)
save your settings.

Open your FTP.
Go to public_html/inculdes/
Open the file called config.php
Look for

$config['Misc']['forumpath'] = '';

Normally leaving that along is fine... (If it is empty try adding /public_html )(Note no trailing slash)

If im completely wrong then Ignore me