screen resolution problems with Hardy Herron

[Linda Hanigan]

I have a very odd problem with the upgrade to Hardy Herron on one of my
machines. When it originally comes up after boot the resolution is fine.
However after you log off, the login screen comes back at 640 X 480
resolution and when you log on the resolution can not be changed from
this either with the preferences nor with ctrl alt + 
So far each user is just shutting down when done. Any ideas on what is
going on or how to fix it. I've found lots on installs that only have
640 X 480 and playing with the xconfig files like we use to have to do,
but x is right on boot so I don't see how it could solve the problem
                  Thanks
                  Linda