I got my MacBook Pro in 2009. I finally purchased Snow Leopard so that I could upgrade. However, every time I try, it says that the disc won't work and needs to be cleaned. I've tried cleaning it, and it still isn't working. Other DVDs and CDs that I've tried work just fine. I'm guessing the only solution to this is to get another copy? If that's the case, do you think Apple would send me another for free (I took the disc right out of the package and put it right into the CD drive--I'm positive I didn't scratch it)?