I have a 2007 Intel MBP, running Leopard. I purchased the family version of Snow Leopard. When I tried to install it, it just spins the disc for a minute, makes the noise like it's trying to read it and then spits it out. All other discs work fine with my MBP so I know it is not the disc drive itself. I have all software "up to date." My brother installed SL on both of his MBs, one newer than mine and one older, just fine (with the same disc). I haven't seen anything out there with this issue so I wanted to start a thread to see if anyone knows how to resolve this issue (beyond taking it back to Apple and exchanging). Thanks for the help.