Ran the search function, couldn't find anything as a possible solution for hosting GR on my g4 dual 1.25gig w/ 768meg Ram, and I'm running OSX.2.6 I am connected to the internet via a D-Link router.
I have disabled the Mac firewall, enabled Internet sharing. I have DMZ'd my D-Link. With these changes, occasionally i'm able to get folks to have their names show up, but as soon as the game starts, they cannot play, nor, if I have "late joiners" allowed, I can see their name in the upper left and corner of the screen saying "so and so entered," immediately followed by "so and so exited."
su