John, try this - Enter an AFMA for an older lens (one without the serial number on the chip, like the 70-200 II), then power off the camera. Turn it back on, and the AFMA menu should show zero and the serial number will be zeroed out (though if you take a photo I'm willing to bet it will still show the adjustment you made). Now without powering off the camera, remove the lens and put it back on (or at least turn it enough so the contacts aren't touching). Go back into the AFMA menu. I'm willing to bet you'll see your adjustment value and the serial number.