Thanks Falko. Your solution might have been more simple. I may have tried it, but I can't remember. Anywyas, this is what I did & it worked. I rebooted and went into recovery mode, then I entered, 'dpkg-reconfigure xserver-xorg'
The text-based graphics reconfiguration wizard came up. Choosing the 'Vesa' driver was the key. (kind of anti-intuitive since I have an ati card and ati was on the list, but...whatever) Another fellow suggested the Vesa Driver and until I chose that driver, the reconfiguation wizard was not going to work.
Also it was suggested that I look up my monitor's horizontal freq. rate and vertical refresh rate in my monitor's manual, so I could enter them directly into the wizard. And I also went into my dual boot XP and wrote down all the screen resolutions so I could enter them correctly into the wizard as well.
And Finally! It worked; it was very satisfying to learn all of this. One slight downer was that I didn't get the absolute highest resolution (1600 x 1040), but the next highest (1280 x 1024). This is still a lot better than 1024 x 768, so I'm sticking with it.
I learned during this that there is a program called Envy, which a fellow suggested would install the accelerated driver for my Ati X1650. And I tried that, and it indeed gave me the highest resolution, but it only worked on my second 15 kernel (not on 16) so that kind of weirded me out, so I actually had to do the xserver reconfiguration again !! So it worked twice for me.
Thanks for your help and assistance,..Frank