Could you try to run '/etc/gdm/failsafeDexconf -o /tmp/xorg.conf' and post the error message you get.
There were some debconf keys that were removed and cleaned from the "real" dexconf but mistakenly left on failsafeDexconf.
Could you try to run '/etc/gdm/ failsafeDexconf -o /tmp/xorg.conf' and post the error message you get.
There were some debconf keys that were removed and cleaned from the "real" dexconf but mistakenly left on failsafeDexconf.