I'm new to Firefox so just installed it the other day, latest ver 9.0.1. Found that running flash videos embedded in a web page has a jerky, hesitating apperance with the sound working fine but doesn't always match people talking. If I scroll it forward with the slider bar, it hangs for awhile. Flash works fine with IE8. I've tried all the usual fixes I've read about;
Uninstalled Flash with the Flash Removal tool, reinstall Flash for Firefox (several times)
Turned off Hardware Acceleration in Flash
Updated Java according to Firefox's plugin check screen
I have a Windows XP sp3 system with 3g memory
ATI AllInWonder 9600 with latest drivers
Any other ideas? It's funny as Firefox runs faster bringing up web pages but then dies on Flash.