> Nope the program rom is a different part number. There should be an undumped Japan > version as well. I'm not an expert on Naomi but I think some games use the bios for > region and others had dedicated region program rom versions.
Wow, I didn't know that. I know some Japanese games require a Japanese BIOS to run. Others behave differently according to the BIOS they detect but I've never encountered a game with a USA region specific program. What happens when you play this cart on a Export or a Japan system?