Here are some more facts that might help in troubleshooting:
1) Every time I set the bank / patch to Factory Content / Showcase / Creamy Poly XS, the patch changes to Classic Tammy WRJ as soon as I play the track. Note that Classic Tammy WRJ is listed just before Creamy Poly XS in the patch selection list.
2) The problem doesn't seem to happen in simple projects that have only a few simple instrument tracks -- although I did create a piece for z3ta2 that had over 30 instances of z3ta2, but no other instruments.
3) In my project, I'm also using Zebra and ACE (by Urs Heckmann). The project as about 40 simple instrument tracks in all.
I really like Z3ta2, and hope that I can keep it in my arsenal. However, if this problem doesn't get solved, I will not be able to continue using Z3ta2. The only work around I have for now is to freeze my z3ta2 tracks, but that creates a lot of other challenges for me.
Thanks.