Which USB port?  There have been issues in the past where certain USB3.0 ports actually are the issue.  Try a standard 2.0 port and run your driver install again (assuming you haven't already).

I had a similar issue at first myself- turned out being the usb3.0 chipset itself (first gen not integrated to the PCH yet).

If you do have this installed in a 2.0 port... where did you get these erupters?