fixed my resolution problem
Thought I'd post in case others had the same problem.
My new monitor was "Out of Range" and the solution was to lower the resolution.
I booted up with the Knoppix 3.8.1 live CD and entered
into the boot prompt and hit return.
So far so good, now how to save the new resolution setting to the hard disc? Poking around here, I learned that the settings are in the files /etc/X11/XF86Config and XF86Config-4. Opened those up with the Konqueror, and sure enough, that's where the data is kept.
Then I navigated with the Konqueror to the same files on my hard disc. Yep, there was the info for the old monitor.
I thought it would be best to copy and paste from the CD to the HD, rather than type it in lest I miss a line. So I gave myself permission to do this by opening the Console and navigating to /etc/X11 on the HD at the same time making backup files in case I seriously screwed up.
Then I used Konqueror to copy both files from the CD and paste them into the HD, rebooted and crossed my fingers. Heh, Linux is great, isn't it? :-D
chmod 666 XF86Config
chmod 666 XF86Config-4
cp XF86Config backupXF86Config
cp XF86Config-4 backupXF86Config-4