Same problem here when I am on the cablemodem,, but it seems to work fine (so far) on Verizon WiMax.
Has anyone posted, asked, if there is a certain set of ports that can be allowed through / forwarded for perimeter firewalls like ISA Server, M0n0wall, CiscoPIX, etc?
I see that it uses a port in the 6500 range for hosting, but is that the same for peer-2-peer connections? What about the proxy connection? That did not seem to work through the perimeter firewall either. Probably because the traffic is initating from the SD servers and then coming back from each host that joins the game?
I've never had a problem seeing the games, but I am unable to join them - behind the FW.
Thanks guys!