Hi Brian - saw the same problem with some Cooled/Modded 5D MkII shots on the Central DS gallery
Go to...
http://www.centralds.net/en/index.htm
...navigate to the 'Gallery' - on the top row next to my LMC image(shameless plug!) are 2 shots by Toshiyuki Sugiur taken with an Astro 5D MkII.
I think you can see the banding at the bottom of the thumbnail image.
Looks like a common problem - that's a hell of a big area to crop out!
Cheers
Doug