Recent reports have noted that the Limited Edition of Halo 3's packaging design did not include adequate measures to secure the game DVDs in place, leading many gamers to find loose, scratched up discs inside the box. Although Microsoft did update its Xbox Disc Replacement Program to include the Halo 3 Limited Edition for free until December 31, 2007 and although most many store keepers made sure to sell undamaged copies of the game, not all gamers succeeded in eluding the problem, especially those who purchased the extremely popular title through an online retailer.
For one reason or another, Microsoft Australia avoided the entire Limited Edition flaw by including one cutting-edge piece of packaging technology inside the game box, known to us simple-minded folk as "foam". A shaped piece of foam pads the inside of the game case and keeps the disc from popping off its center hub. Perhaps Microsoft manufactured and shipped Halo 3 to U.S. retailers first, with the later worldwide shipments taking place after an internal packaging revision. Future North American shipments of Halo 3 Limited Edition will likely include the special foam.
News source: DailyTech