I have a Nikon F2 that I bought second hand. Nearly 2 out of 3 shots show a distinct double image on the right side of the photo. No other body I use exhibits this, and it happens with any lens I use. The photos have been taken around the 60th to 250th speeds. It is not blur as such, but a clear second image. Two technicians have examined it but can see nothing wrong. Has anyone else come across this problem?