If the books are in a collection and the title is unexpectedly changed, weird things can happen in my experience with a KT, so most probably with a KK as well.
Make sure you delete the old copies,
unplug the Kindle and let it notice they are missing, and then send the new copies.
Alternatively, delete the collections they were in and rebuild the collections from scratch (or via the Kindle Collections plugin). Obviously this is the hard way.
