What kills Gnome??

[Beartooth]

On one of my FC5 machine (but not the others, including one running
FC5.ppc) I am unable to login under Gnome. When I tell it to, I may get a
brief flash of a login display with the F-infinity logo, or I may not;
then it goes to a plain solid dark blue screen, and stays there. Lately --
since the last reboot but one -- clicking on Session doesn't even offer
Gnome. 

I did "yum install gnome* gnome-*" -- and that didn't help, either.

I suspect that I've done some bad thing trying out pup or pirut, removing
some app whose name meant nothing to me, and now discover I needed it
after all. 

If so, how can I find it? Or could something else be wrong?

-- 
Beartooth Staffwright, PhD Neo-Redneck Linux Convert
FC5; CXO 5.0.1; Pine 4.64, Pan 0.14.2.91; Privoxy 3.0.3;
Dillo 0.8.5, Galeon 2.0.1, Epiphany 2.14, Opera 8.54, Firefox 1.5
Remember I know precious little of what I am talking about.