Reply to VCI 100SE Freezing???

My VCI 100SE locks up when I am using it (Traktor no longer responds to it), it happens at any given time and I have to unplug it from the computer then plug it back in to get it to work. I recently upgraded to Traktor 3.4 the Tech Tools v.1.3 tks, the hard drive to 200GB @ 7200rpm and the ram to 2G so the computer should be fast enough, I also tried using different usb cords, anyone else have this sort of problem??????