I expanded the subsection again with the latest pre-release without a hitch and then tried it with the previous release and it also expanded properly so I'm not sure what was going on but when I originally tried to expand my subsections twice, the second section of the three would only play one of several instruments and I'm sure I didn't have it selected to play solo.
Once for some reason I had success with the sections expansion, when I rendered to audio about five of the instruments didn't show up as audio tracks.
I deleted any instruments that I wasn't using even though they were frozen, repaired disk permissions and rebooted and thawed all the tracks. I rendered the tracks to audio again and it worked correctly.
Also when I render to audio the instrument names will be different such as trumpet 2 would be trumpet 21 or some such thing. This only happens when working with a large number of instruments so I assumed CPU stress was causing that error also.
Well, I just rendered that file to audio again and Trumpet 1 is now Trumpet 13 and Trumpet 2 is 23. 3 is 36, Tuba is Tuba3, ect. There are random numbers after all the instrument names. I forgot that also the audio tracks were not assigned to audio ports but to remaining midi ports and have to be changed manually for the audio to work.
Phil