Comment 13 for bug 183922

acuozzo, thanks for attaching the Xorg.0.log. Unfortunately, it does not show error messages or a backtrace relating to the crash; usually this appears at the end of the log. You might look to see if you have an Xorg.0.log.old that contains the crash backtrace.

Make sure you have the dbg symbols for xserver and your video driver installed. Info on this is available at https://wiki.ubuntu.com/DebuggingProgramCrash

If that doesn't have a backtrace (and sometimes even if it does), we may need to have you gather a better backtrace. Instructions on doing this for Xorg are available at https://wiki.ubuntu.com/DebuggingXorg. Since you're experiencing an exit crash rather than a lockup, I'd recommend sshing into the box and invoking X in gdb, run it until it crashes, and then use the command 'backtrace full' to get the trace. Copy that into a file and attach it to this bug report.

Once we know what X call is getting triggered to make X exit, it'll help identify where checks can be inserted to prevent the behavior from occurring.