Comment 45 for bug 938658

I'm still positive that my experiences and yours are related. Furthermore, I find Scott's theory very interesting. I'm running Ubuntu on a Samsung R710 laptop, my graphical memory is only 512MiB. I'm getting these blank-outs quite often, especially when the whole system is outmaxed.

I'm experiencing black-outs every now and then when restoring minimized windows. When the restored one was maximized, sometimes you can see the ones behind blank out. They restore when the focused window is minimized again.
When handling small (not maximized) windows, the effect is more visible. It doesn't make a difference how you restore the window, it just happens randomly.

Open ccsm, go to Animations -> tab Focus Animation -> under Animation Selection click the only entry -> set focus effect to Dogde and duration to something between 300 ... 500. You will then have the effect I've been talking about earlier. Windows will blank out much more often when raised into focus now.

It seems that every time a window has to be animated when raised into focus, this issue might occur, no matter how it is activated. Perhaps the animation effects cost too much video memory.