Hello Gary,
Thanks for the help. I realized that if you can't see the banding
effect I described, then it wasn't in the file, but in my display.
Just to furter check, I loaded the .jpg file into Photostyler and saw
that there was no banding in the file.
I reconfigured my display using the VIBCGF. The only change I has made
when the banding started was to up my resolution to 1024/768 at 65000
colors. By reducing it to 880/600 at 16mill colors, the bands
disappeared. I guess, at the higher resolution, I don't have enough
colors to show the real image.