I see a few bugs with IE7. One is that the "upload image" box does not work (see Browse button in Image insertion doesn't work in IE7). The buttons are out of place and "Browse" does not work correctly, so I cannot upload images.
Also, on /privileges pages (like http://meta.stackoverflow.com/privileges), the percentage column is shifted down and does not align correctly with the name of the privilege.
I'm using IE 7, version 7.0.5730.13.