I have had this problem. It seems to have been related to a recent 'nvidia-settings' update. The date of the original 'bug' seems to have been a while ago which worries me whether my issue is related to this bug but the steps to reproduce are similar. I can't disable second monitor. Deleting x.org.conf then rebooting worked temporarily but problem persists.
-- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to nvidia-graphics-drivers-updates in Ubuntu. https://bugs.launchpad.net/bugs/1071334 Title: NVidia Settings fails to disable the second monitor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-updates/+bug/1071334/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp