GNOME Bugzilla – Bug 668149
xscreensaver and gnome-screensaver conflict in Preferences menu
Last modified: 2012-01-18 01:03:49 UTC
If you install xscreensaver, and then gnome-screensaver, you will get two identically named 'Screensaver' entries in the System -> Preferences menu. Removing xscreensaver resolves this. Perhaps making the two packages conflict would resolve this in a simple way. Reporting from Ubuntu: https://bugs.launchpad.net/ubuntu/+source/xscreensaver/+bug/21960
So, GNOME doesn't currently do packaging. Sounds like an Ubuntu bug to me.