Actually, this is an interesting scenario. It may well be that AC did not change anything to their site but that somehow, a great many people inadvertently updated some browser component (with this "automatic update" feature, which is ideal to get viruses, spyware and the like). And that the updated browser component is broken, or that somehow, given that AC designs around the idisyncracies of the MS browser instead of the standards, some bug fix in the updated component broke the AC site.
In any event, using Firefox (on Linux, but that should make no difference), I don't have a problem. I wonder if anyone else *NOT* using IE has a problem? (I love the irony here. Especially given their claim that their site is designed to be compatible with IE, and their offensive/arrogant warning whereby *my* browser is incompatible.)
Textbook case on how not to do business on the web, anyway. Especially given how long this seems to have been going on with no solution. Heads should roll. Heads should roll. Except, I have the nagging suspicion they won't.