GA-Z68MX-UD2H-B3 USB 3.0 port will not open USB 2.0 storage devices

I have just assembled a Windows 7 PC using a I5-2500K processor,
GA-Z68MX-UD2H-B3 motherboard, 4GB of RAM and a 250 GB Seagate HD. Drivers were
downloaded from the Gigabyte site and installed after the windows installation.
Everything seems to be working EXCEPT:

When I connect to the USB 3.0 ports a Sandisk Cruzerblade 4GB USB flash drive,
an older .5GB Sandisk USB flash, A Seagate 1.5GB USB, or an older 250 GB Maxtor
USB drive, the device is not properly identified, and cannot be accessed. All
these devices are USB 2.0 drives. If I connect a WD Mybook USB 3.0 drive,
everything works fine. Connecting a USB 2.0 mouse also works fine.

The Cruzerblade shows USB Amss Storage Device, driver 6.1.7601.17514 and
Hardware Ids USB\VID_0781&PID_5567&REV_0200 when connected using one of the USB
2.0 ports.

Using the USB 3.0 port, it shows Unknown Device, the same driver #, but "No
drivers are installed for this device", Hardware Ids show as USB/Unknown.

I've tried unloading, re-downloading and re-installing the Etron USB 3.0 driver,
with no improvement.

Can anyone offer suggestions on what the problem is or how I can track it down?