Hi, all! Thank you so much for your answers.
I'm trying the nuclear method, so wish me luck.
I've done around 15 books and it's puzzling. My first non-fic had a table of contents and I had to do maybe 2 adjustments, which were very minor. It surprised me how much of an issue these latter books have been. I've been on some of them for weeks. I don't use any word processor aside from Word. I've had the program for so long (it's 2003), I am very comfortable with it. I've created copies for Kindle (.htm) and Nook (.epub) from the same file and both of those are fine. It's just Smashwords and that bothers me because it's so convenient.
I have no issue with fiction, it does excellent. The only exception is a short story anthology, which had a table of contents.
However, I will try you suggestions and thank you for them.