I just received a Plugable 7 port USB 3.0 hub from Amazon and connected it to a MacBook Pro (not Retina) running Mountain Lion. I have found that I can connect a USB 3.0 device to only ports 5-7. If I connect either of the USB 3.0 devices (Seagate GoFlex 1TB USB 3.0 or Lexar 64GB USB 3.0 Jump Drive) to ports 1-4 the hub light is on but the device isn’t recognized. In the case of the Jump Drive, the light on the Jump Drive blinks once then goes out. It should continue to blink if it’s connected. USB 2 devices are recognized on all ports. Thanks
I’ve also received your contact at firstname.lastname@example.org and we’ll be happy to work with your directly to get your up and running.
I have the same issue on a late 2012 iMac 27".