I just installed the latest updates for Karmic, rebooted, logged in, and was idle long enough for the screensaver to active. Upon doing so, I had been returned to the GDM screen. To test, I logged back in and chose "Lock Screen" on the main menu, to which my session was terminated, and I again found myself at GDM.
Binary package hint: gnome-screensaver
I just installed the latest updates for Karmic, rebooted, logged in, and was idle long enough for the screensaver to active. Upon doing so, I had been returned to the GDM screen. To test, I logged back in and chose "Lock Screen" on the main menu, to which my session was terminated, and I again found myself at GDM.