Hey everyone! I am on OS X Lion and I have a MacBook Pro (Early 2008) and a MacBook Air (mid 2011). An external hard drive is connected to my MBP and it is in the list of Share Folders in System Preferences under Sharing. I want to back up my MacBook Air using Time Machine by using the hard drive that is connected & shared by my MBP. However, when I choose a disk in Time Machine preferences I don't see the shared external hard drive. How do I back up over my wireless network? Thanks!