Uninstall the Flash plugins and try new ones. Also, turn off this setting (see google.)
-> DISABLE FLASH HARDWARE ACCELERATION.
Recently, out of the blue, whenever I try to watch videos on youtube on Safari or Firefox the video screen turns pink with purple lines momentarily and then my Mac freezes up for 1-2 minutes. Of course at the time it unfreezes i close the browser or else it will freeze again. I can only watch videos on google chrome. What's happening? Should I re-install the other browsers or could this be a sign of another problem? Mac Os X 10.6.3