Topic: CSS: Background-image and style switching.

I'm having some trouble understanding background-image and how browsers store them.
http://www.cs.orst.edu/~terrasi/cardv/default.php

One thing that's a problem at this point is the toolbar. Everytime I hover out it, Mozilla 1.0 will re-request the image, so that, even after the page is loaded, we see the image loading. It kinda sucks. I don't know if I should just peg it as a 1.0 bug, hopefully fixed on 1.1, or whether it's something a bit more insidious. Opera and IE handle that part perfectly.

Another problem is on the style-switching links (under the beef appreciation paragraph). In Mozilla, works fine. In IE, when I click on Simple CSS, the entire central div (div id="#content") is invisible, but as soon as I resize the window, it shows up. I'm assuming this is a bug with IE, but exactly what bug is it? What is triggering it?

Thanks
-D