Russ, I'm sorry to say I've never encountered this problem, or no anyone else who has. Are the zoom lenses loose in the mount? Do all your zoom lenses do the same thing with the camera? You don't list lenses in your profile, so I have no idea what lenses you have. Is this happening with Nikon zoom lenses, and non-Nikon lenses? What about prime lenses? Does it happen with primes at all?