I have a MacBook 13". Whenever i put in a Dvd, the os x reads it as a blank dvd. And this happens everytime i do it. I sendt it in to repairs, and i just got it back, they said they couldnt find anything wrong with it. I quote "changed combodrive. Tested OK with Known Good OS. Problem is in costumers software. Needs to reinstall with own CD." Thing is, when i took it home, the same problem was there, all dvd´s are read like blank disks. And im here thinking "how the F*** do i reinstall when it wont read my reinstall disk" Sorry for my french. Anyways, what do i do?