FC2 Gnome/KDE went south on me

[Bruce Ecroyd]

After a week of running stable on a new install of FC2 (non SELinux),
something 'blipped' and now I can't log in via either KDE or Gnome
(hangs). Xfce is fine though. Most applications start up normally
under Xfce, but Evolution won't start up. All of the 'up2dates' had
been applied as of today.

I'd (ideally) like to get things back without reinstalling FC2. 

Anyone have any thoughts on things I can try to see if I can isolate
what's happened?
(or a recovery mechanism).

Bruce