This sounds very similar to this bug in gnome-screensaver, with a similar setup (multi-head with nvidia drivers): https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/71030
-- Screensaver & Wallpaper doesnt work https://launchpad.net/bugs/68125 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
