As my patch to add a global lockdown key was commited (see http://bugzilla.gnome.org/show_bug.cgi?id=386864), we should use "/desktop/gnome/lockdown/disable_lock_screen" instead of "apps/panel/global/disable_lock_screen".
-- disabling lock screen does not work https://launchpad.net/bugs/50761 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs