Just fired up Icy Box IB-351 IDE/USB external hd enclosure, after pulling the usb cable from the usb port I thought I noticed a spark, I then tried to re-create it and low and behold, if I touch the i/o shield/case with the usb cable there is the smallest of sparks, I tried different cable and still the spark. I have an older icy box ide/usb and tried it with that, no sparks. Touching the usb cable on the sparking icy box has no ill effect on one, no feeling of electricity at all.

Is the enclosure faulty, has anybody got a recent icy box and can create the same?