Update on vBadvanced.
Whoever had the problem with this not working with the portal,
You can fix the login by looking for login.php in the
ad_header_end template of this theme and add
http://www.yourdomain.com/forum/
before login.php
Then search for the other links such as search.php, forumdisplay.php, calendar.php etc in the ad_header_end template and add
http://www.your site in front of those as well.
This will allow you to use this theme login box and the added links with vbadvanced.