Using my Knoppix CD was the ticket. I can't believe I didn't think to do that.

Thanks to both of you for your suggestions.

In case anyone follows this thread and isn't sure how to do it, here's a step by step.

  • o Boot to the Knoppix CD
    o Start an xterm (or some other command line interface)
    o mount your existing partition. For example:
    (sudo mount -t ext3 /dev/hdb6 /mnt/hdb6)
    o copy your current config file
    (sudo cp /etc/X11/XF86Config-4 /mnt/hdb6/etc/X11/XF86Config-4)
    o reboot

Darren