A lot of posters on Bungie's site have been complaining about Halo 3 disc read errors. Apparently different players are unable to access different things on Halo 3. For instance some are unable to use the Forge, some cannot play certain maps in multi-player, and some can't even play the game. What's going on?
Here's a link: http://www.bungie.net/Forums/posts.aspx?postID=13193500&postRepeater1-p=1