Comment 28 for bug 220019

@Rowd
I guess your issue is a different one so I would create a new bug report. Please attach your /var/log/Xorg.0.log there and try to get a full backtrace like described in this howto https://wiki.ubuntu.com/X/Backtracing.
Are you sure that you had the correct adaptor number while testing Overlay with mplayer? If you use the wrong one mplayer normally uses textured video with the Debian Sid driver. An easy check is to enabling compiz, open the video and then press shift +alt + cursor up. If the video is scaled down texture video is used. If you only see a part of the video in the small player overlay is used.