vbulletin google adds targeting wrong

[Thug]

using google ads on many sites work fine, automaticaly target what i want them to target no matter what domain, however on http://www.oh-twadi.com forum their targeting the wrong type of sites.

-could this be due to php sessions
-forum being so largly populated with usernames all over the page
- or headers on vbulletin

what could sort this??

cause phpbb works PERFECT with adds,and vb is ment to be better so how come it wont target