Hello. This is my first post, and I joined this site because I've had this re-occurring problem. Let me firstly start by telling you that I have used three different keyboards, and two different mice, so it can't be either of them. When I'm on a website, or any screen which has a scroll bar on it, (Adobe Flash, web browsers etc) every so often, the screen jumps up, (scrolls down) and I have to move it back up. This, as you can imagine, is really annoying when using any art software or game which uses scrolling. I've searched the net umpteen times, but never found the answer. Could any of you know the problem at all? It can't be unique to me. Thanks, in advance.