I'm leaning toward exactly that: two servers on the same computer.
This would be buggy for the manual clearly states that this can be done with different session names and ports. However as indicated in another post, I'm not to clear that the ports are working as they should which could be related to this error.

Why would you suggest I run game_net in server/client mode? How would that make a difference? Are you suggesting for debug purposes (ie: f11)?

EDIT:
Tried game_net as server-client... didn't help and actually hurt the game for unexplicable reasons