No those should be controlled by CSS (Firefox obeys the W3C standards and Internet Explorer does not) VBulletin and Invisionboard if they overwrite these standards are in fact NOT being modern, they too are acting like Internet Explorer and using their own ideas/methods instead which is wrong.

UBB is attempting to follow the W3C standards and where possible implement known "hacks" to try and get Internet Explorer to obey the rules as best as possible. IE7 is much better but still quite a ways off from obeying the standards.