Comment 8 for bug 188660

> Could this be a compiz problem, causing the X server to crash?

Could well be.

> Can you please try to get some log files, like Xorg.0.log?

I tried, but without much luck. "sudo /etc/init.d/gdm stop" didn't stop gdm,
as you suspected. I also tried killing the gdm process (or processes, as
ps showed a parent and child gdm process), as follows:

On my first try, I just killed the parent gdm; this caused the X server to die
immediately, leaving me in text mode but with no shell prompt. I switched
to a different virtual console with alt-ctrl-f1; this one had a shell, and I typed
"startx" at the shell prompt. This started an X server with the default stipple
background and "X" cursor, but no Gnome desktop. Should I have run
startx as root?

On my second try, I killed both gdm processes by listing both on the "kill"
command line. This caused the machine to lock up (the desktop remained
visible, but did not respond to keyboard or mouse commands), and I had to
reboot.

Anything else I could try?