Comment 11 for bug 455073

Quote: "It seems it doesn't happen if you don't move the mouse after going to fullscreen. Once you move it, you need to go off and back on to fullscreen if you want to stop it popping up every 7-8 seconds."

I was wrong, it still happens. Only unchecking 'Disable screensaver' stops it, but then, but then screensaver appears on set time.

@Mr. Blonde: Thank you! That fixed it.