Update on 'unstable' left Gnome unusable

[Larry Elmore <ljelmore@home.com>]

I'm running Unstable with kernel 2.4.2 and performed an update using
apt-get yesterday. At first X was dead, but I was able to get it running
(it never asked me whether or not to overwrite /etc/X11/XF86Config-4,
but certainly did so). Now, however, I can't get past the gdm login
screen except by selecting Xsession instead of Debian or Gnome. It
simply resets back to the login screen. I've tried everything I can
think of, to no avail. Any suggestions?

Larry