I recently got a copy of leopard single user. I installed it on my machine. Without realizing it, my brother installed the same copy on his computer, but it allowed him. Are we going to run into any troubles? I thought that since it is already installed on one computer, it will not let you install it on any others? Or is the single use the exact same as family pack, but with a family pack you are legally allowed to install on more than one computer?