Sorry for the false alarm? I don't understand but it all started working again now that I'm trying it again. I wonder if it had something to do with the fact that I'd stopped in play-back half way through, then backed up a little and played it again... etc.
Otherwise could it have been a copy-paste thing? I copy and pasted the Master Close item across each staff to save me a little time and I have 3 staffs (a piano and a flute) down and two repeats per staff, so maybe that did something bad that got cleaned up when I switched the repeats to-and-from-and-back to master repeats.
Anyway, all seems well now. If I can figure out how to reproduce the problem I'll check back.
Peter Edwards, I'm new to this forum. Do I just copy and paste that "code" into a file and open it with Noteworthy? (I'm at my work computer so I can't try it until I get home...