Display settings fail to apply on 13.04 with Gnome 3.6/3.8 [duplicate]
Solution 1:
I solved this by removing every config file (~/.*) from my home directory. Previously I had attempted to remove all gnome related files but this didn't help.
(I followed: How do I reset GNOME to the defaults?)
I still don't know what old config file caused this, but I recommend moving all your config files to a backup directory and moving them back one by one. If you want to test if this will help, login as a guest and see if you can reproduce the problem.