d'oh! I'm under Debian (unstable) and I use to browse ONLY with mozilla-firefox (now 0.9.x) ...
Also Epiphany, IE ( lol... ), Konqueror, lynx... and I don't have blank pages...
Try opening my vbulletin:
http://www.wellage.net: te module is loaded on the bottom-right of the home page and works fine.
The module is just a chunk of php code and some html.. just a blank page? vBulletin in case of minor error (like a error in a module) doesn't stop his execution ( = blank page).
A) Does the needed template exists in the style you are using?
B) does your account have privis to receive that page? ( I mean... Are you logged with the same account of IE - check cookies - in Firefox? )
Without error messages I can't imagine what happens, but don't worry: we will find a solution!
...
C) just to be sure... when you set unactive my module all works fine?