I just upgraded to 10...and now links and buttons black out when my cursor moves over them, and my entire window goes black whenever I scroll.
I just upgraded to Firefox 10 and had to go back to 3.6 because 10 doesn't seem to work on my computer. I have a windows 7 pc. After upgrading, whenever I moved my cursor over a button or link, that link blanks out or a black bock appears over it. Additionally, whenever I try to scroll, the entire window goes black until I stop scrolling.
I'd try starting Firefox in Diagnose Firefox issues using Troubleshoot Mode. If you don't have the issue while all of your add-ons, extensions, and themes are disabled, you can try adding them back in one by one until you find the culprit.
Hopefully this helps!