I don't know. I connect automatically but are you talking about how there's a check for add ons before you load the game? You're saying the add on (Dawnguard) won't show if you're offline? All those quests just disappear from your journal?
yeah pretty much then i get a message when i try to continue on with my game dawnguard is on my hdd but if i'm not connected to xbox live dawnguard is unavailable to play