I bought a 15" MBP from the Apple Online Store on 6/16 and it wouldn't recognize my serial number either. What did you guys enter for the city and state for the online store? It wouldn't let me submit without one. (wouldn't take the serial number with or without the city/state)
I put both Austin, TX and Cupertino, CA, and it took both (no bold red needing correction), but my serial number still won't work.