I recently purchased a used D3 and expected the shutter count to read about 7000. I have no reason to doubt the seller. When I used Opanda, the shutter count was at 4, from the few test shots I took when I received the camera. Original owner has no clue why this might be - never serviced, minimal use. File naming is consistent with the reported 7000 count (DSC-6794, for example).
Anyone have any idea how the shutter count gets reset without full blown service call to Nikon?