I have the same problem. gnome-session 2.16.0-0ubuntu2 had a fix for not grabing the display when a composite manager was running, but it does not detect the use of xcompmgr.
-- session logout freeze https://launchpad.net/bugs/63772 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
