Recently, I've noticed my XR2S' light meter has been acting off, after shooting a frame, the meter would keep running until I advanced to the next frame. didn't think much of it until earlier today, when the meter spontaneously started jumping all over the place, before giving me weird readings and not changing even when I changed lenses and pointed it directly at the sun. does anybody know what's going on and what/if I should do to fix it?