You could put a US_NavalBase on one of the Japanese main islands, and the game wouldn't care. Might be a bunch of explosions and smoke, but it won't freeze the dials. The main thing to look for is something conflicting with the player's submarine, and ninety-nine times out of a hundred you'll find an AI submarine is to blame. You probably have equipment ID conflicts in the DAT or SIM or etc. files causing issues.
