通过游戏中心(GameKit)通过3G发送和接收数据停止工作

I have a Game Center matchmaker working and implemented, and by using Game Kit's Bluetooth functionality I know that my multiplayer code works. When playing over the internet through the Game Center sandbox, it works when both devices are on WiFi, but if one is on 3G it quickly stops sending and receiving data, and so the game grinds to a halt. Does anyone have an idea why on earth this is happening?I have a Game Center matchmaker working and imp