I also encountered this bug. I ran gnome-screensaver --nodaemon --debug for a long time, and noticed that when the screensaver wasn't working correctly, the debug output includes lines like
[manager_maybe_start_job_for_window] gs-manager.c:207 (21:33:38): Not starting job because throttled Prior to that, the throttle is being toggled on and off for a while, but it seems to get stuck for some reason. If I restart gnome-screensaver with $ killall gnome-screensaver; gnome-screensaver then things start working again. ** Attachment added: "debug output: lines containing "throttle"" http://librarian.launchpad.net/5077704/t -- screensaver starts first time but not after https://launchpad.net/bugs/68950 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs