[oclug] I've clobbered my system!

[master]

Help!

Yesterday I used software installer/remover to download a couple of
extras in the mistaken impression that I'd get a better selection of
screensavers than the defaults offer.. The items were : 

xscreensaver-extras-gss
and
xscreensaver-gl-extras-gss

Some time after I had done this, I left my system for a while (when it
was operating properly) and came back to a wrong-sized screen (no lower
menu bar) and my LCD panel indicating that it was trying to reset
itself. I couldn't do anything on the system and it wouldn't even log
off. So I used the escape mechanism of CTL-BKSPCE, logged out and
restarted : I came back into X only regardless of which user I was (i.e.
it even happened under root).

Now all I get booted into is the X system and I have to call up anything
I want to use via xterm.

What did I do wrong? How can I do a quick fix without having to do yet
another install (which has been my approach in the past)?

I have looked at several of the system files but there's nothing that
seems to me to contain anything that dictates how GNOME starts up or
what actually starts it (I am usually in GNOME after I boot up).

Oh, I am using Fedora 8.

Any help (especially quick!!) will be most gratefully received.

Thanks

CroombeFP