-how to fix your screensaver after ubuntu oneiric ocelot wipes everything out:
+how to fix your screensaver after ubuntu oneiric ocelot or later wipes
+xscreensaver out:
this page has good info about most of what's needed:
http://www.webupd8.org/2011/10/things-to-tweak-after-installing-ubuntu.html
this page shows how to get menu working again:
http://ubuntuforums.org/showthread.php?t=1865593
+
+
+this directory also has a file containing a slightly modified version of the
+fix for the gnome screenlock menu item. it's called screenlock_dbus.py.