Same on Dell 640m Logout dialog should not accept his own duplication.
Some other victims of this bug were failed here : https://launchpad.net/ubuntu/+source/gnome-power-manager/+bug/31104 -- Problem with shutdown button https://launchpad.net/bugs/86470 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
