User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b6) Gecko/20100101 Firefox/4.0b6 When using the auto-scroll, a square of the area of the page the auto-scroll was originally on is moving down the page with it. Reproducible: Always Steps to Reproduce: 1. A good example website is http://www.dailymail.co.uk/home/index.html but it has been reproduced with others 2. Hover your mouse over some non-white area of the screen and press the middle mouse button to start auto-scrolling 3. Drag your mouse and you should see a square area of screen the auto-scroll was hovering over is moving down the screen with it This may be graphics card dependent so I'm currently using a geforce 9600 gt