On Saturday I was in the Apple store in Glasgow and thought I would ask one of the 'geniuses' what type of card I needed to buy to add more USB ports to my new mac pro. He told me that I couldn't add a card as there are none available. Is this true ? He mentioned PCI-E2 being a factor, surely it's backwards compatible ?? And genius or not, his 'know-it-all' attitude was less than friendly.