I don't know if this has come up before but I didn't find anything on a quick search. I recently bought a Thunderbolt Express Dock. The ethernet port is working. However when I plug in my Iomega, 500GB firewire hard drive into my dock, using the firewire port, my MacBook Air, running Mountain Lion, is not picking it up at all. The same occurs when I try it via the USB ports. However plug the hard drive directly into my MacBook Air and it shows up and mounts. Anyone know what I might be doing wrong? The Express didn't come with any instructions so I assume it should be a simple plug and play. I've not tested my other hard drives yet. I have three firewire drives I'd like to daisy chain, two being Iomega devices, as well as three separate USB hard drives, which I plug in from time to time. Thanks for reading.