https://bugs.freedesktop.org/show_bug.cgi?id=35697
--- Comment #12 from Nikos Chantziaras realnc@gmail.com 2011-03-27 19:28:16 PDT --- (In reply to comment #11)
[...] If UnredirectFullscreen=false fixes the problem then it really sounds like it is bug 35452 and that xserver patch should help. Without that patch and unredirected rendering you should observe screen corruption in most other fullscreen apps as well, esp. when they switch out of fullscreen mode. At least Compiz is almost unuseable without that patch with unredirected fullscreen windows.
This isn't the case here. There's no screen corruption whatsoever without that patch. The problem I'm having with Flash never results in actuall screen corruption either. It's mostly a black screen, a system freeze or the screen just "hangs" and only the mouse is able to move. I never observe any corruption (which I understand to mean "random garbage" on the screen.)
The frameskipping with redirected windows is probably because the compositor doesn't run at the same composition rate as the redraw rate of the app or the refresh rate of the monitor.
I've set MaxFPS=60 in kwinrc and my monitor runs at 60Hz. I guess KWin isn't good in keeping things synced, that's why it skips frames.