Comment 7 for bug 358643

I looked a little bit more into this, and there seems to be a
difference in whether I use /dev/ttyS0 /dev/input/wacom as the
"Device" in the "InputDevice" section. /dev/input/wacom is a symlink
to /dev/ttyS0, but maybe the driver doesn't realize that it it a
collision if the different names are used.

I have tested with the attached xorg.conf where I have stripped away
most of the stuff that was irrelevant for this bug. With
  Option "Device" "/dev/ttyS0"
uncommented, X crashes already on startup (it keeps restarting for a
while after boot). The screen flashes several times between general
corrupted screen and black during this and finally stops in the
courrupted state.

With
  Option "Device" "/dev/input/wacom"
X starts just fine. During the first X session VT switching works
fine. At logout, though, the X-server crashes and when gdm comes up
again the VTs are corrupted. They still work as I can run commands
blindly, but after switching to a VT I cannot get the X-session back.

Finally, when commenting out
  InputDevice "stylus" "SendCoreEvents"
in the "ServerLayout" section, everything works fine no matter which
line I use in the input device.

I attach Xorg.0.log for each case, two for the case of
/dev/input/wacom, since I don't always get a crash with a backtrace in
the log for this case.

Let me know if there is anything more I can test.