I've always wondered how restore disks were tied to a specific machine. For instance on my MacBook Pro and Mac Mini, the 1st disk is labeled as an OS X 10.5.6 install disk... When you examine the disk, it looks to be the same as a Leopard 10.5.6 retail disk as far as contents are concerned unless I am missing something. Would they work interchangeably on these machines like a normal leopard disk? Supposedly they are not able to be used on another machine, but how can that be if they are simply copies of Leopard. Can anyone shed light on this? Thanks!