Hi All - I recently hooked up a new USB 3.0 hub to plug all my peripherals into my new 27" iMac. (Started out with a 2.0 hub which worked fine). For some reason after plugging in the 3.0 hub, my computer will just hang on the white screen while booting up. I finally installed my old 2.0 hub back and the computer boots up fine. Does anyone know what I may be doing wrong?