I am using Ubuntu 12.04 LTS..
In most cases, when I put a video in a Full screen on YouTube (I am not using HTML5, I am using Flash Player), and when try to exit the full screen mode, I got my screen turned to a blocking white screen.
This prevents me from doing anything on my box but restart from ALT + F1 terminal.
Actually I don't know where exactly to report this issue, so I put it here appreciating any help.
PS:
I could see this issue on 13.04 also.