After entering my posting earlier today, I did some more internet searching on this problem. I found a helpful British website that listed a trick for cleaning the printer carriage area. It's a little more than halfway down the page, if you click on this link,
http://www.valueshop.co.uk/printing.asp
Here is what they suggested:
"1. OPEN printer so the cartridges move to center of the carriage.
2. REMOVE all cartridges.
3. FOLD a letter size piece of paper in half, and then in half again the other way so it is quartered.
4. START with the long, folded edge and insert into front of printer where paper normally feeds out. (it will slip in a little over halfway)
5. MOVE the paper left and right to remove any excess ink under the carriage. When the excess ink is removed the printer should print streak-free. "
I tried this (actually used 3 or 4 pieces of paper because it was pretty grungy), and I can print without bands of gray now. Although, the colors are not as vibrant as they used to be, neither is the black. (My holiday newsletter looks good enough to send out, at least.)
After cleaning the printer carriage area, I ran the nozzle check pattern test again and it still looks bad. I then cleaned and realigned the print head, and again the nozzle check pattern continues to look bad. The user manual for the F60 (page 10-5)said that if the nozzle check pattern does not improve after a deep cleaning then the printhead may be damaged. I called Canon tech support and they think that the printhead is probably damaged, but they suggested that I take it to an authorized Canon repair shop, which is too far away, and probably too much trouble. My other option is to order a new printhead directly from Canon for $45 plus $6 shipping and install it myself (or make hardware engineer hubby do it ;-) ).
Hopefully this trick for cleaning the printer carriage area will help others at least for the short term, like it helped me. Good luck!