PgDrawImagemx() is doing the SIGSEGV

our app is attempting:

PgDrawImagemx( rgb, Pg_IMAGE_DIRECT_8888, &pos, &ext, ext.x * 4, 0 )

In older versions of libraries and/or Photon, it worked OK.
‘rgb’ is a pointer assigned with PgShmemCreate(), using plenty of memory.

Any suggestions on how to debug this ?

BTW: ‘sin ve’ shows:
sys/Proc32.424G Proc 4.24G Aug 25 1997
sys/Proc32.424G Slib16 4.23G Oct 04 1996
sys/Slib32.424A Slib32 4.24A Feb 04 1997
//2/*/photon/bin/Photon Photon 1.13D Jul 07 1998

I’ve tried various combos of older versions of Proc with no success.

TIA,
Ron Groenenberg