https://bugs.freedesktop.org/show_bug.cgi?id=29738
--- Comment #5 from Till Matthiesen entropy@everymail.net 2010-08-23 17:17:27 PDT --- All I can tell so far is that it looks like this behaviour was introduced somewhere between 2.6.35-git2 and 2.6.35-git3.
As Alexandre said, it is not straight forward to trigger. I might (don't think so) have missed it in 2.6.35-git2 but X crashed with 2.6.35-git3 shortly after a few resizes of the mplayer window.