I noticed that when the user has activated the Compiz / Compiz Fusion and want to see a Flash movie (YouTube type) on fullscreen, the film keeps running while the image does not update.
To solve this problem its necessary to open the Terminal and execute the following command:
mkdir -p /etc/adobeecho "OverrideGPUValidation=1" > /etc/adobe/mms.cfg
After that, reboot your machine. Solved Problem!