Comment 12 for bug 388250

Unfortunately, this bug report is still missing a useful backtrace. From looking at the current trace, the 'minor_code = 7' is a clue that the call which triggers the error was XRRSetScreenSize, which doesn't match the call in the existing backtrace (XRRSetCrtcConfig). This means that the error actually occurred some time in the past, so the backtrace here isn't a lot of use.

Could someone who can recreate this issue please try to obtain a backtrace following my instructions in comment #7?

In addition to that, it would also be useful to have a look at what happens at the protocol level, by capturing some information using xtrace. In order to use xtrace, you first need to add the following line to the "[security]" section of /etc/gdm/custom.conf (creating one if it doesn't already exist):

"DisallowTCP=false"

Once you have done this, please log out and back in again (or better still, restart your computer to make sure you get a new X server instance with the required configuration).

Once you have logged back in, please do:

killall gnome-settings-daemon
xtrace -D:9 -d:0 -k 2>&1 | tee ~/xtrace.log #Replacing :0 with the number of your X display
DISPLAY=:9.0 gnome-settings-daemon

Then try to recreate the issue and attach the resulting log file to this bug report once gnome-settings-daemon has crashed.

Thanks