I downloaded 2 map packs on my xbox 360 at my friends house becuase i do not have live at mine. so i took it back to my house and tried to play the map packs on halo 3 but the maps did not show up. i have been tring everything i can for the past 2 days. does any one know how to make the maps show up. do i have to be always connected to live for me to play them.? please help