>> Iceweasel 3.0.4 & Debian Testing
That's what I'm using (Iceweasel is just a rebranded Firefox) except that it's version 3.0.9.
I do appreciate the trouble you're going to. As you might have guessed, I've just changed energy supplier to Southern Electric, and I need to access their website to submit meter readings. For the moment I've had to use IE6 with the Wine emulator, which is a less than ideal way to do it.