That symlink may well work if you're using GDM. If you start Gnome without using GDM, though, it still locks up.
Aside: Shouldn't the name of the GDM socket be an environment variable, passed down from GDM to gnome-screensaver just like all the other sockets, D-BUS, SSH agent etc... -- screen does not unlock after locking https://launchpad.net/bugs/76632 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs