submenus won't appear MF3 se----newbie flummoxed

[osha]

I have 3 clips up on the main menu and I have a few chapters added to
each clip , but the submenus with the chapter thumbs don't appear. Once
you add chapters to a clip , shouldn't the submenus automatically come up
when the main menu clip is clicked or do I have to set up the submenus in
a separate operation? I didn't click the hide option when I set up the
chapters and the show option was preselected so I clicked OK , went back
to the add/edit page and then to setup menu page and clicked on one of
the 3 clips and only get the change thumbnail box, not the submenu with
chapters. What am I missing? Thanks for any suggestions!