My macbook pro was connected to my TV and playing Netflix "full screen" mode. I disconnected the display port while it was still in Full screen mode. The Apple display went back to its normal full resolution, but the next time I tried to play Netflix without the TV hooked up on Firefox, the screen would go black when I hit the Full Screen button.

Reinstalled Silverlight. Cleared my cache. Contacted Netflix. Contacted Silverlight. No solutions. Strangely, it continues to work when the TV IS hooked up. It also works in Safari. It ALSO works when Safari is open, but I am using the Firefox browser. It does not work when Firefox is the only browser opened and there is no TV connected. Help!