Comment 4 for bug 86416

I will try to fix this in the next version. The xscreensaver package actually ships /usr/share/xscreensaver/gnome-screensaver-properties.desktop but it is hidden with NoDisplay=true. It's like this in Debian because there the xscreensaver package is not split up like in Ubuntu, and therefore both xscreensaver and gnome-screensaver are installed, and the unused one must be hidden. We don't need to hide it Ubuntu.

Can you please edit /usr/share/xscreensaver/gnome-screensaver-properties.desktop and remove the NoDisplay=true line and see if it fixes your problem?