Weird. FF12 works just fine for me. So does IE9 for that matter, but I'm more used to the FF interface so that's my browser of preference. I still use IE9 from time to time since it works so much better for certain (work) websites. I have 11 tabs open across 2 instances of FF and I'm at about 350MB of RAM. I don't really have any plugins running aside from AdBlock Plus or whatever it's called.