Slitherine

I'm having problems starting a multiplayer game with my friend. I'm logged in I then issue a challenge as the germans to my friend, he says that he accepts it, but I don't seem to start the game as the germans, the system says the game has started but the game doesn't begin. We try again, and after three tries the systems has me time out. Now that kinda of rediculeous. Why should I be prevented from accepting or issuing a challenge while nearther challenge has resulted in the start of a game? I'd like it if someone with spell out the procedure step by step so that me and my gaming partner can finally being a game.