Multiple domain support & vBulletin?

[ScEmH]

Hello. I help maintain a site that has roughly 30 domains, and for quite a while now the other staff and myself of the site has had major difficulties in making the vBulletin support all of our domains.

What are the problems? vBulletin uses the value for "Forum URL" (Under Site Name / URL / Contact Details) to construct most of its links. Now that's fine for anyone who happens to view our site with the same domain used in Forum URL, however for anyone using a different domain they're going to experience many problems. Problems such as not being able to log in, links that use domains other than the one the user is using.. etc.

We've tried leaving Forum URL blank, setting it to ./forums or /forums, but in each case there's always something broken with it, be it IE support or broken links in the Email Verification / Subscription Notifications sent from the forums.

We've considered setting $vbulletin->options['bburl'] to $_SERVER['HTTP_HOST'], which may work. However, I've no idea how to properly make a plugin do this for me.

I'm really out of ideas for fixing this. Anyone else experienced this problem or know of a fix? Any help will be appreciated.