Hi Zafar,
That is a very strange problem that I have never seen before. The only other possibilities that I can think of are:
1. The pc has a different version of of the Microsoft SDK than Nov 2007 (see my instructions PDF)
2. The pc has a mechanical problem with the port or the cable.
3. The USB port has a problem - try another USB port (USB 2.0).
You said it works on another machine. Have you tried it again? It may have failed after you put it on the last pc.
Other than that, I am stumped.
Lee