hello, maybe it's an issue with the protected mode in the flash plugin - you could try if disabling protected mode makes a difference.

I disabled Protected Mode too but still no changes i revert back to flash player 11.2 its better than before but still not acceptable

now i don't use Firefox for Facebook and YouTube till actual fix comes.

for youtube you could activate the html5 player - then most videos can be played back natively without using flash: http://www.youtube.com/html5

Thanks that was useful but still Mozilla or Adobe have to fix this ASAP

I've given up on firefox, I'll use Chrome now, I'm not happy about it but firefox truly sucks bad now! Guess thats what happens when you have to many cooks in the kitchen? Can't believe that I went from loving firefox to truly hating it! You will be hard pressed to get me back, I'm beyond discussed!!!

http://youtu.be/QqFeBKkbFl0