[jonathan lall]

I agree that the fact that it is "their fault" is no reason a web browser shouldn't safeguard against these things. To a point. There's a difference between people who aren't computer savvy, and people who sign contracts without reading them; this is essentially what you're doing when you hit OK to every dialogue box that stares you in the face. It's certainly just as ignorant, and as such, blaming the web browser's designers is more of a copout in certain cases.

I personally don't believe it's good UI to highlight Cancel either. If someone wants to download something and hits Enter, he/she will expect it to come. The aformentioned un-savvy people are going to run into problems if IE were to do that.