Question on "clean install" of Snow Loepard. Since I an eligible for Snow Leopard "upgrade" for $9.99. Am I getting a full version for a clean install or do I have to reinstall Leopard first and then pop the "upgrade" Snow Leopard DVD in? Also, Can I install Snow Leopard "upgrade" on my other Macs without buying a Family Pack? All the Macs are under my name.