If you bought Halo 2 Limited Edition, you dont have this problem. The Halo 2 DLC has a problem of loading all the DLC. Bungie must of removed it or it just cant find the DLC. Does anyone else have this problem? I've contacted bungie about this Issue.
Im pretty sure if your using the 360 platform that they took the dlc down. Seeing as how as off april it won't be supported, you could always go and try to find the dlc disk and try that. Of course you won't have tombstone and desolation.
Ive seen a few announcements made by Bungie saying that there was an update and everyone needs to download the maps again (it has happened a few times). Just try to download them, they are all free.
Not to sound like an asshole, but I hate pointing things to people! #1: (DLC Disk): The DLC Disk isn't being sold anymore. This is 2010. You think that there selling a Limited Edition 2004 Game. #2: (Mikelp): God I hate people who cant read! YOU CANT DOWNLOAD THEM. The DLC Content has a problem or Has been removed by Bungie. Bungie must half to remove the DLC maps from multiplayer in order to play online MP!