For those of you who are really getting into CSS it may be worth a look at the following two links. As I understand it, both of these attempt to put all browser based settings back to zero (as they should be); enabling you to then add your CSS uninterrupted by the oddities that the browser tries to trip you up with! In theory.
Tripoli by David Hellsing (watch out, html 4.0)
http://www.monc.se/tripoli/index.html
Eric Meyer
http://meyerweb.com/eric/thoughts/2007/05/01/reset-reloaded/
Richard Eskins 