I have a new Macbook Pro running Snow Leopard. Please Note: I do not want to change external hard drives, but I want to change the LOCATION of my external and HOW the external is connected to my Macbook. I have been running Time Machine, backing up to my WD 1TB Passport external drive via USB cable. I would like to lose the "umbilical cord" and connect wirelessly to the external via my (newest model) Airport Extreme base station. I want to do this without losing my previous backups. When I connect via the AE, TimeMachine gives me the choice to backup to this drive but it starts from scratch, making a whole new backup. When I click to "Enter Time Machine" it gives me the choice to "use previous disk" and when I click to "use selected disk" as in my screenshot, it allows me to peruse the old backups, I just am not able to continue backing up to that backup. I would like to backup via the AE, but then also have the choice to remove it and connect directly via USB on occasion and continue the same Time Machine. Is there any way to do this, or is this wishful thinking?