Thanks, Hitch. I said it was mysterious.
The cover looks like
The
The
XXXXXXXXX
XXXX
Except that the second The looks to be 'in front of' the first The, and a little of the first The is covered by the second The. And the XXXX is not completely over to the right; it overlaps the XXXXXXXX
The author and editor specifically refused permission for me to send the screen shot to the forum. I'm only the ebook designer.
One think I've noticed since is that calibre has a different setting for Kindle Voyage than for other Kindle models. I use the straight Kindle setting. I don't know if that's related.
Thanks again for your trouble. The Kindle Voyage user, the author, and I have agreed that this is one of life's great mysteries, and have moved on.