https://bugs.freedesktop.org/show_bug.cgi?id=30406
--- Comment #7 from Martin Stolpe martinstolpe@gmail.com 2010-09-28 01:20:47 PDT --- That did the trick. Thank you!
After adding Option "2DAccel" "TRUE" to my xorg.conf moving windows around is working again.
There seems to be a problem though. It seems that some characters aren't displayed anymore at the titlebar of windows.
I've created another bug report for the OpenGL problem: https://bugs.freedesktop.org/show_bug.cgi?id=30412
I think this bug report can be closed.