So, strange, but I'm not having this problem anymore. I was having it ten minutes ago, updated, was still having it. Then i fiddled with some books so that I could attach a few examples and, retrying but re-ordering the merge, it suddenly worked. And then I retried it in the other order (that hadn't been working before) and it worked fine. So...the update worked? I guess I'm good for now.
Something I did notice - this is only happening with epubs made using
squeebooks. Maybe it's something about how the books are made with that site? Whatever it is though, I'm not having that problem now whether it's the update or magic.
Thanks for being willing to take a look anway.
