did you push the power button after hooking it to the usb cable to turn it back on? i dont see that part in your post... it wont turn the phone on for ya.. you have to do it...
disregard if you already kno that part...
But i have had mine not see the phone 4 or 5 times b4.. i just had to restart my pc and it would work... seems to happen if i flash too many times between restarts of the pc...