Ok so I go received my RETAIL copy of Leopard last week in the Mail paid in full for One User on my mac pro. Now I also have a new iMac that is still awaiting my Upgraded copy in the mail, it shipped last week on the 25th but still hasn't arrived. There are some issues with apple not even being able to track, but they claim it will be here by the end of this week on early next week. Now seeing as I have a copy coming in the mail, is it breaking the EULA Agreement if I go and install my current RETAIL version on my iMac? Can it even tell that Multiple computers have the same copy? I know there is no serial or anything like that, but what about when I register? Should I just wait it out? What would you do?