Light on cant read Audi Masterd disks

Not a big thing but my Liteon x48 cant read disk that use Audi Master from my F1. It just sets there and looks dumb. My Plextor can read them and my Car CD player can too. But whats up with the Liteon? It can read disk that are not Audi Mastered from the F1 but it just hangs from a cd that is a Audi Mastered one.:confused: