As new browsers are released, and new browser versions emerge, how do you know the parsing bug or feature you are relying on will not be removed or modified. How comfortable do you feel about your web page, application being future-proof when you are using a css hack?
I mean, you have lots of people who have based their hacks on features that IE doesn't support, and suddenly IE7.0/8.0/9.0 etc comes along and now IE supports these features (but the rendering bugs haven't been fixed) and will now be able to render the rules that weren't meant for IE.
There is also a readability issue. Did you notice how Eric came with a "piece of css", and then Bear Bibeault didn't understand it. Well, that kinda underlines the point.
These are just my thoughts, though,
Regards, Roy [ July 06, 2006: Message edited by: Roy Ivar Moe ]