Re: Netflix/Silverlight quit working, is Firefox 10 a 64 bit browser?
June 30, 2012 - Here is the best solution to this problem. Uninstall Firefox, and all your personal preferences. Then go to Program File(x86) folder and delete the Mozilla Firefox folder as well.
Go the Real Player application and Preference. Then uncheck the "Enable Web Download and Recording from these installed browsers" box, and select the “Don't show (download is only assessable from right-click)”box. Close Real Player.
Do a registry cleaning with wherever registry cleaner you trust on your system.
Reboot your computer.7
Reinstall Firefox. Your problems with Neflix and all streaming media are now solved.
It worked for me.