I have a CalDigit FASTA-6GU3 in my Mac Pro 4,1 and I want a usb hub so I don't need to reach under my desk to plug stuff in. I tried to use the Anker® Uspeed USB 3.0 4-Port Hub Ultra Slim and just plugging in it caused a kernel panic. The CalDigit card works well when just plugging drives in directly, but the hub seemed to be causing the problem. (or at least the card didn't like it). Has anyone with this CalDigit card used a good USB3.0 hub with any success?