I thought Mozilla had changed their decision on that.I've got Windows 7 and I use Firefox.
I'm not even that html5 thing, mostly because my browser doesn't support "h.264".
This. It also auto updates flash player for you. If you want to stick with FF, try opening it in Safe Mode with no addons.Use Google Chrome.
Chrome has themes too.Though, I still miss the changeable personas and stuff like that for Firefox.
IS SAD