Every once in a while during gaming my controller simply stops responding. I've tried plugging it into several USB ports on the front and back of the tower, I've tried rebooting the computer and updating the drivers, and the problem persists.
Have you tried using a different cable? Some cheaper ones are not all that good at surviving gamer (ab)use 😉
I used a different USB cable and now it works just fine but I'm disappointed that the official Charge and Play kit from Microsoft was such garbage. Oh well.