Comment 4 for bug 42652

Sven,

please re-run dpkg-reconfigure after exiting your session, and stopping the gdm service. (sudo invoke-rc.d gdm stop)

This step is supposed to fix your setup. If it doesn't, please follow the steps described at https://help.ubuntu.com/community/DebuggingXAutoconfiguration, and attach the output of the requested files in this bug report.

Thank you in advance for the feedback!