I received my 3 today.  2 worked perfectly - almost plug and play.  Overclocked to 53 with negligible rejects and HW errors around 0.35%.  The 3rd unit registers as a USB device but can't be found by bfgminer.  My hub hasn't arrived yet so these are plugged directly into the computer but I've tried every usb port and no dice.

I am very new to this so I wouldn't be at all surprised to find out I'd missed something simple.  Any thoughts?