I have a brand new 3TB Seagate external hard drive with both the USB3 dock that came with it and the optional Thunderbolt dock. I used my new 3TB drive in the USB3 to transfer some files from another hard drive that was in the Thunderbolt dock. Now when I put the 3TB Seagate drive in the Thunderbolt dock, it says the disk is unreadable and wants to initialize it. I've tried restarting pulling the power cords etc. I tried it on my laptop and it now does the same thing. Works fine now via USB 3 but will not work via Thunderbolt. What the heck is going on? I really hope I don't have to keep this as a dedicated USB3 drive. Thanks for any help!