percentages and ie
In an earlier post I had a proble with padding and later learned from another thread that IE does not recognize percentages when dealing with padding and margins and borders. Is there a reason for this? are there other places where IE will not recognize percentages? Even better is there a website that possibly lists what else ie can't or won't recognize?
there are a good number of "quirks" that microsoft recognizes it doesn't support. IE7 is getting better at correcting some of those, but since it is the latest build out, not everyone has it, so you do need to give support to IE6 and even IE5.5... and I think it would be safe to say that you could "force", eg tell them they need to upgrade, anyone with a build before IE5.5 as it is becoming much too obsolete.
but as for what IE will and wont support, the best is just to do a search on google / search engine of choice, and also microsoft home site, as they will publically admit what they dont support, for bugs / non-compliance when it comes to css.
in another year or so, I think it would be safe to say that you could even force IE 5.5 users to upgrade to at least version 6, which has much better support for CSS 1.0 than its predecessors.
Really what you should be doing is attempting to get them to stop using IE all together, and use a browser that supports standards, like FireFox, or Opera, or Safari, Netscape, etcetc...