Since I'm not seeing anything obviously wrong with "my" code (and there's not a lot of it, and it's not too complex), does anyone know if there is anything in any of the standard "include" files that can clash with the ISOMETRIC flag? The following standard files are being included in my project:

#include "gid01-c.c" // copy of global ids
#include <acknex.h>
#ifndef gid_wdl
#define gid_wdl