Seems to be an xorg bug to me. What do you expect from the capplet? Do you want it to workaround the xorg bug somewhat?
-- Screen Resolution tool fails to switch between MergedFB "dualhead" and "clone" modes https://launchpad.net/bugs/41610 -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
