Technical issues with Heroes III.

Hello! We have a problem when playing with three players: we play through GameRanger, and the last player to connect (it doesn't matter which of the three) "disconnects" from the game when Heroes of Might and Magic III starts (the game tells the other two players that he has disconnected, but in reality, he sees the first player's turn, he receives messages, but his turn doesn't come). When two players play, there are no problems. We are located at different ends of the city, using different providers, and all of us have routers; the firewalls seem to be configured correctly. We all use Windows 7. Please help!