I'm having this same problem and trying to figure it out. This guy seems to have fixed it, and it makes sense with the menu's being in an absolute position, but I don't know enough about this stuff to know how to fix it.
Code:
Problem solved.
If vBulletin is inside a div with position: relative; the dhtml menu looks bad because in clientscript\vbulletin_menu.js (line 229) this.menuobj.style.position = 'absolute'; the position of the menues are absolute.
As soon as I take out the align="center" from the first <tr> it moves everything to the left and it all lines up fine.
So how do we fix this?
By the way, my website is
http://www.northwestfirearms.com for example of what it's doing.
--------------- Added [DATE]1229717482[/DATE] at [TIME]1229717482[/TIME] ---------------
Someone here has to know how to fix this, it works for the search dropdown menu at the top of this site.