S0C1 - User PGM - GBP Problem?

One of our Natural user program in production abended with a S0C1 and 954 under CICS.

After the program was refreshed from Natural’s Global Buffer Pool, the error went away. The abended program has not been changed.

No close printer (zap on SL24) and no MOM (queue problem) was involved.

Surprisingly, the program was running fine under TSO (other GBP).

We are running Natural 4.2.3 update level 3.

Any thoughts?

Thanks,
Dieter Storr