Thanks for the reply, Keith.
After I read your response, I checked ALL my results, and I've discovered that many of the books I've built DO indeed show the chapter markers. I am strongly suspecting "Operator Error", as the ones with no markers are the earliest ones I built. They are also the ones I'm listening to first, which is which prompted me to write for help, without having reviewed later-built books (I wasn't kidding about the addiction part!).
Your succinct description was very helpful to me, and I'm sure will keep me from making similar mistakes in the future.
Don't lose any sleep over it, but my husband is holding ABB to blame for the new 500 Gig hard drive that recently showed up on my desk.

GREAT product!! And no more late fees at the library!
Theresa