Now I have a new problem but obviously related. This has taken 24 hours to develop.
When I use the scroll wheel, the screen goes completely blank for a few seconds, just as if the plug has been pulled. It then returns as if nothing had happened. Why this didn't start happening yesterday I don't know. I haven't had a mouse crash yet but this new problem, must be something to do with the way I have my video card or drivers set up.