Thanks for your quick response Raja!
I have the same issue on both the UEFI 0801 and 0902 bios. The USB hub is the SIIG USB 3.0 4 port hub (http://www.siig.com/usb-3-0-4-port-hub-1063.html). This device is QVL approved.
I have the strangest issue. If I plug a USB Hub into any of the USB 3.0 or 2.0 ports in the back of the PC, 90% of the time it will not boot to Windows 8.1 (even if there are no devices plugged into the hub. Sometimes it just hangs at a black screen with a cursor blinking in the upper right and...