Hi there, I have a USB disc drive for my mac book air as well as an external hard drive. I'd like to plug the USB disc drive in, insert the music CD and upload my music to my iTunes folder on the hard drive. Unfortunately, the Disc Drive (the MacBook Air Superdrive) only work when I plug it in direct to the MacBook - not through a USB splitter. As the Air only has one USB port, I can't also plug the external hard drive in. How can I get over this? Thanks.