Update: When I said the screensaver doesn't start, I mean that the theme doesn't start, ie you get a blank screen.
Also, I just found that logging out and in does (sometimes) return normal behaviour... -- screensaver starts first time but not after https://launchpad.net/bugs/68950 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
