I downloaded MS3 the other day, but every time I load up the game I get signed out of XBL automatically. When I select multiplayer and the XBL feature, it asks me to sign in...but it never does. I can play all of my other games, including XBL Arcade games, online without any problem. In fact, I get a strong signal when I load up a multiplayer Doom deathmatch. Anyone else having this problem or have an idea of why this is happening?