The problem is, when plugged in, they both take the same "slot", eg both appear as P1 if the wirless units are off - and only the last to be plugged in actually works. I've tried using different USB sockets on the Xbox, which makes no difference. There are several instances of this problem on the various online forums, but no definite solution that I can see. Any suggestions? Unfortunately the supplier has no more in stock and there is a risk that if I get a direct replacement for one unit, this will be no better.
