The Halo series has always been about addictive multiplayer experiences, so it's most disturbing to find out that campaign co-op gaming on the latest title is a non-starter for people without a hard drive attached to their 360. An issue has been identified by users of the 4GB Xbox 360, whereby attempts to team up on the baddies with your buddies -- whether locally or via Xbox Live -- is met with an error message saying that a HDD is "required for this game type." This affects both
