We get a hourglass icon and a waiting for players message after playing for a while:

For one reason or another some of the systems have stopped communicating with each other
• Usually if you wait a moment the game will continue, however, if it does not there is probably a more serious problem.
• Try disabling music on all of the systems.
  • This should free CPU time and resources. This allows the game to devote more of its time to networking.
• Make sure that you close as many background programs as possible. If your still having problems click here.