I've got three problems with IE 8.
1. One website I got to (Ranger-Forums) will show the basic forums, but not the individual posts, it throws up a white screen and covers the post. Works fine with Firefox.
2.CBS News website, the archived news video's won't open up to a full screen, doesn't open up with Firefox either, so it's a W7 problem, it works great with XP and Vista.
3. CNN news video's won't play with IE8, but play fine with Firefox.
Other than that, IE8 works great for me, and I'm using it quite regularly.