Damnit! It doesn't want me to play your game!
Hmm... I don't really know what I'm talking about, but a quick google suggests you might need to flush your DNS cache.
On windows you can do this by going to Start>Run type "cmd" and press Enter. Then in the console window, type "ipconfig /flushdns" and press Enter.
For other operating systems, just google 'flush DNS'. Hope this helps.