From HighDefDigest.com:

Universal Breaks Silence on HD DVD Playback Issues; Announces Disc Replacement Program | High-Def Digest

“Universal is currently investigating reports that Children of Men, The Good Shepherd, and select other discs not playing properly in some HD DVD players. While we believe this is limited to a small number of HD DVD discs, Universal is offering a replacement service for any customers who are experiencing this problem. We are still investigating the cause and will provide further updates as we get them. Any customer problems should be directed to USHE.ConsumerRelations@worldmarkinc.com.”