Here comes the brother of the K-7 vertical green line bug, the vertical green banding of the K-7!
http://forums.dpreview.com/forums/readflat.asp?forum=1036&message=33389418
Well, I think this careful-minded K-7 user has a very clear description of the phenomenon and problem. The banding does not always appear. But when it appears, once appeared, all ISO speeds are affected.
Do note he has updated to the latest 1.13 sub-version of the K-7 firmware 1.01 already but problem persists.
Read Also: Updates on K-7 Vertical (Green) Line Bug