In an earlier effort to install system sources (somehow gone horribly wrong), I ended up with some important files being overwritten - most significantly, /etc/passwd and /etc/master.passwd (I have no idea what else). I recreated the user entries, but a number of other important entries are still missing and I don't know how to repair them. When I boot the machine, it complains about the following unknown users: avahi, polkit, haldaemon, pulse, and gdm. The machine seems to run fine as long as I don't start gnome, but hangs when I do. How can I go about fixing this? Delete the gnome2 package and add it again? I'm hoping for something quicker. Thanks for any help.