OK, so here is my current problem.  We have a 'server' running Ubuntu 7.10 and it has been up for 1.5 yrs now.  Every day it has one purpose, to periodically reload Firefox.  The firefox homepage is a company marketing flash video that we use for window eye candy.  All of a sudden, we get a startup error along the lines of:

User's $Home/.dmrc file is being ignored. This prevents the default session and language from being saved. File should be owned by user and have 644 permissions. User's $Home directory must be owned by user and not writable by other users. 

At this point I can ssh in and try to fire off the firefox script below:

#!/bin/sh
export DISPLAY=:0
killall firefox-bin
date >> /home/stk/log
firefox -fullscreen

However, when I run this I get this output:

(firefox-bin:2626): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
Xlib: connection to ":0.0" refused by server
Xlib: Invalid MIT-MAGIC-COOKIE-1 key

(firefox-bin:2626): Gtk-WARNING **: cannot open display:

So I am working on this now.  Nothing has changed on this server, and I am fairly certain auto updates are off, so I am not sure what gives.  Will post solution when it's available.

UPDATE Aug. 10th, 2009, 2:11 PM:   After my friend Kevin pointed out that GDM must be corrupted somehow, I issued the following to reconfigure GDM:

 sudo /etc/init.d/gdm stop 
 sudo dpkg-reconfigure xserver-xorg

Which resulted in a slightly modified error when trying to launch the firefox script:

(firefox-bin:2606): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
_X11TransSocketINETConnect() can't get address for localhost:6000: Name or service not known

(firefox-bin:2606): Gtk-WARNING **: cannot open display:

So back to the drawing board.