Ok, partially answered my own question. Maybe.
I ran another conversion of a different file, (call it "story 2") which was an azw to mobi, and the 5-way controller works for jumping chapters. I'm pretty sure that IS new.
However, the conversion mentioned in my first post (call it "story 1") was regarding a Word doc saved as html converted to mobi. That one is NOT supprting the 5-way controller. To test a theory, I just sent this Word doc to Amazon for conversion, then ran THAT azw through Calibre. Sadly, still no 5-way action. So, can I assume it's something inherrintly wrong with this doc? Although not done by me, I happen to know that Story 2 was originally created from a doc sent to Amazon, so I'm a bit baffled why it's working for some and not others...
Thanks and sorry for not having my head screwed on tonight...
~Rach