When i load up the shangri-la map from the annihilation map pack that I have downloaded. It loads up and then the music stops and the icon in the corner saying call of duty black ops then on the other side says treyarch, freezes and i am unable to play the map. however i am allowed to use the Xbox guide button. I also am allowed to use the online maps which come with the map pack. I have contacted xbox live and run through tests with them to make sure the download is correct and there is no problem with the xbox, they said it is fine and told me to contact your company. I have checked forums, but it seems this is not a common problem.