Interesting, I am unable to repro it with that film back. Are you cropping at all? Is there anything else that sticks out on your camera that I could try to add here?
Either way, we have a repro, and Eric is looking into it. There has to be some sort of rounding error somewhere.
And there’s no need to thank me. Thank YOU for reporting these things! It’s next to impossible to catch regressions with all the automated and manual testing we do each release.