I have a powermac G4 with a pioneer dvr 107 8x superdrive. all of a sudden I cannot read dvd at all yet cd of all types work fine. last night I watched a movie on it and all was well. it will not read ANY kind of dvd media (blank or with data). I have tried dvd movies, dvd+r I have burned, dvd-r I have burned.. everything whats up? why is it still reading cd ok? is there some way to reset it? i'm thinking I may need to buy a new one.