after u recently updated to 3.6.2 i've been having problems, at times the menus on anything firefox wont show, i can see the shape and shadow but they're transparent and videos can appear choppy and out of sinc, yet IE is working perfectly
i've ran all spyware and virius stuff while in safe mode and nothing was dected.
I'm still on 3.5.8 on Ubuntu Linux, and I am not having these problems. Do you have an option of trying it out on different operating systems?
it seems i'm not alone and there a large thread on this on firefoxs forums, i downgraded to 3.5.9, and all seems to work now
cross's fingers