Alan Swartz , Apr 11, 2010; 03:11 p.m.
I have no certain answers for the inconsistent readings. Undoubtedly there is an electrically intermittent connection somewhere, perhaps in the camera, in the prism, or at the mating contacts.
But there are two meter movements. The shutter-speed needle you see in aperture-priority mode is in the prism. The aperture needle, seen at the right side of the focusing screen, is in the body.