I did that - kinda. I saved as a new project. then deleted the menu and chapter links in the body of the AVIs. Then re-created the menu anew and established the chapter links anew, but still same problem (selectable in preview , but not from the platter).
I think I'll try the idea of simply creating a new project from scratch and bringing down the AVIs that compose the project. One this note, to add a detail about my situation: my project is not one menu, one avi, but one menu and about 12 AVIs, four of which were linked to chapters in the menu. Again, this composition worked fine before I added a fourth avi entry on the menu.
btw, the "create iso, and burn with another tool" approach resulted in the same problem, so it is not in the burn part of the process that is bad.