https://bugs.freedesktop.org/show_bug.cgi?id=30188
--- Comment #12 from Maggioni Marcello hayarms@gmail.com 2010-10-06 01:34:19 PDT --- I found another situation where xorg crashes. Bringing virtualbox fullscreen makes the x server crash immediatly, but this time not with a sigbus, but with a segfault.
another backtrace attached