This problem has just started happening after my xbox crashed.

I load up my xbox, it signs me into xbox live. I load up PoL and it disconnects me from xbox live when I do so. It loads the game And I log in and it then asks me to connect to xbox live, when i try to do so It says it can't connect and to check my connection. I can return to the dashboard and sign in fine again. Any ideas of wtf is happening?