I've got a silly little niggling problem with my mouse. It is currently a new Logitech Cordless Optical Mouse, before that it was a Browser Mouse, not that it matters. It is just that the scroll wheel sometimes does not work, roughly every other time I use it to scroll down a page. It worked perfectly until about three months ago with the Browser Mouse, when I at last got fed up with it only working when it felt like it I bought the new Logitech but it is just the same. I've checked the settings of course, and it is set up alright as far as I can see.