I have a question, which has probably been answered, but given the mess Snow Leopard has caused on here, I'll ask again.
My Father in Law has my old 2006 white 17" Intel Core Duo iMac. That model obviously came with Tiger preinstalled and came with Tiger restore discs. He has since upgraded to Leopard with a retail copy I bought to upgrade, however he has gone and lost the disc.

So while he's upgraded to Leopard, will he be able to upgrade to Snow Leopard, or will Snow Leopard ask for him to insert the Leopard DVD into his iMac for confirmation?
My 20" Core 2 Duo iMac, bought in March this year, came with Leopard installed and the Leopard restore discs, so I know I am fine regardless. However my Father in Law would like to upgrade, and if his carelessness has caused him to lose out on Leopard then I'll upgrade and rub his nose in it.
Many thanks.