Comment 76 for bug 107093

Davi Vercillo C. Garcia

If Flash works in Opera (e.g. Youtube), then I guess you could use that instead. If Flash doesn't work and/or you want to use firefox, I guess we can try to find a fix.

First, what version is your flash plugin in firefox?
Type in "about:plugins" (no quotes) into the address bar and see what's under Shockwave Flash.
For example, mine is like this:
Shockwave Flash
    File name: libflashplayer.so
    Shockwave Flash 9.0 r124

Second, you could try turning compiz off. This will turn off all the eye-candy, though.
To turn it off, replace it with metacity. Run (Alt+F2) "metacity --replace" (no quotes).
To turn it on, Run "compiz".

Metacity is more light-weight than compiz. I use it when watching movies or when I need more performance.
If Firefox works well under metacity, then it may be vga-related since compiz is more GPU-hungry.