Problem w/Priority, Aperture, Program Modes
You certainly have a poser there.
Have you tried other exposure modes - spot, matrix, center-weighted?
Have you deleted any user setups? (pg 5-13)
Have you tried a resetting to default (pg 5-12)
Have you tried a different lens?
Finally, have you tried the two button reset (pg 5-23)
Assuming all these are ok, I would look to the contact pins on the mount ring. This how the chip in the lens communicates with the camera exposure processor.
Oh, one last thing, have you doubled checked your ISO settings on the meter and camera?