I think this is happening only when we use the mouse with a desktop PC. I think so because I've used this mouse(Microsoft wireless mobile mouse 4000) with my laptop (dell studio 1558) for about 3.5 years. It worked like a charm and I loved it. Recently
I brought a new desktop and started using this mouse with my new desktop. It worked for about 3 weeks and then the nano receiver gave up. Now, whenever I plugin the nano receiver to the usb port of either my laptop or desktop, initially an error message pops
up which says, 'usb device unrecognized' and after 1 minute or so, the nano receiver becomes too damn hot.
So, I think this particular model has problems with desktops (as they have greater voltage fluctuations). It might work fine with laptops.