I had the same problem but got it resolved, my front usb ports were "sticking". sometimes they would work, other times they wouldnt. I opened my PC case and made sure that the connections were tight and they were but when I inserted and wiggled my bluetooth dongle, it worked fine. found out afterwards I had been trying to push the USB`s in too hard ( not saying that you have ) and I had dislodged the connection ports. Have a try at that otherwise, make sure that the USB ports are clean from dust ( sounds silly but trust me it causes probs ).
Hope this helps