Speaking of non-sequitors, has there been a discussion of the possibility of cameras using contrast autofocus to periodically adjust the phase-contrast system on their own and remember the correction for that lens? Would the camera need to be at a known distance to do this?
No but AFMA can be distance dependent. AFMA on any lens should be at the distance you expect to use the lens the most. AFMA at or near infinity does not always mean your macro lens will AF correctlyat macro distances. I've found this to be the case on many wide angle zooms.
I got the Err 70 a couple times in the past. I chalked it up to one of my cards not playing nice, but it's good to see that it's not and that there is a fix for it. Just in time for my Walt Disney trip.