Can't play anything in Flash Player sometimes

[MasterClock]

Sometimes when I try to play YouTube videos or flash sigs they don't work.  On YouTube it plays the first 2 seconds without sound and then stops completely.  Flash sigs just don't work.

This usually happens when I have several tabs open, and the problem does not fix itself (by removing tabs) unless I force quit Firefox and restart it.

Anyone know the problem?

[Safe___Clock]

I was just about to make a thread.
I googled it and it said to reinstall or get that flash player with the exploit fix.
Haven't tried it though