I think I've made some progress with this theme in Internet Explorer. At least on my localhost windows machine. The sidebar on the front page should be where it's supposed to be, and the blue block boxes should be aligned.

Some of the problems seemed to be with the background: declaration in the stylesheet not being the first thing listed. (Yeah, I just threw them where ever my cursor was. When I moved them, they appeared. Funny, Firefox had no problem with this...)

I still need to fix a few things, but at least it's more readable now.