It could be how you've modified the stylevars or css or possibly this:
http://www.vbulletin.com/forum/conte...-Profile-Style.
Although there's not many stylevars under profile that should make it end up looking like that... if you have not modified the stylevars or css then it's the last one otherwise you'll need to look for the definitions in userprofile.css it's within the CSS Template family when editing templates.