I had similar issue with NikonScan, and sent it to the service for repair. After cleaning everything works fine.
I was hoping you might share where did you sent it for repair and how much they charged?
Did you find that the scans worked well when scanning color transparancies but yeilded these type images only when scanning B&W?
I have just been told that I had the Silverfast software set so the 9000 was trying to scan at 6000DPI which is way beyond its stated resolution of 4000 DPI and the scanner was unable to interpolate at that level hence the banding and ghosting.. I HOPE they are correct.