I think that the orange background is just too heavy. It may be a lot cleaner if you made the content's background white, then left the orange as the background... something like the screenshot attached.
I'm on FF2... and the main navigation menu at the top shifts all over the place (it was a mess). Did that happen for anyone else?
I haven't looked into that problem, but I can guess that fixing the errors may help:
It's a really nice layout, but I think it can definitely be cleaned up a little (especially the code). Good job with it though.