Well, I've had no response from the Windows help forum. I am beginning to suspect that it's because I use neither IE nor Active-X and I'm not about to start now.
Something slightly new has just happened. I opened this page to write this reply and the mouse is working perfectly in it so far (and the page, including the blue bit at the top hasn't gone pale) but I tried to click the "Start" button to open Speccy so as I could list this machines spec. to see if FOR thought that it looked like his (see his last post) and my click didn't work. I'll try again later!