[DragonforceIV]

Yeah; actually, that's because Vista is making Internet Explorer more hacky and virus prone so when people are struck with a problem on IE; they'll move over to Firefox. In fact; I like Firefox also because of the multiple add-ons for it and I can make it look like a Mac as well!

To the topic:

Have you tried uninstalling and reinstalling Firefox? That usually does the trick for quite a few problems. Also are you using the Feedback Manager for Firefox? If you are, then they'll eventually find a cure for it. If you aren't, it's a great idea.

Best of Luck!