Thanks
Althought there has been a 'technology upgrade' patch to the dev box I feel its something related to 32/64 bit mode. Whether this is OS patch related is proving difficult to determine.
The compile of the COBOL program isnt striaghtforward becuase I have to compile under 64 bit, then move the excutable & bind files over to the usserid running in 32 bit mode.
Looking at the dump the seg fault core dump the line
Segmentation fault in _iwzEnvNameInit
points to the goback command at the end of the program (see
IBM - SIGSEGV _iwzEnvNameInit)
But like I said this prgram hasn't changed.