Any suggestions on how to repair a focus selector switch on a Nikon 80-200mm 2.8 AF-D ED lens (not the S type)? It is the small chrome button on the selector switch (the ring type) on the lens. It no longer locks into positions, which means that when I am manually focusing the lens, I might slightly move the selector switch and it will kick out of AF or M mode. The button does not feel springy as it did prior to getting messed up. I was thinking of getting a small rubber washer and fitting it under the button. This would raise the button making it easy to lock in either AF or M mode. Other alternative would be usinf a piece of tape under the ring to keep it from moving. Is this something I can repair, or should I send it to Nikon? Any idea how much Nikon would charge for this type of repair?