I'll start with:
1. Use System Restore to when it worked.
2. Sounds like a video driver issue. DO NOT USE DRIVER UPDATE buttons or software. Do this update the old fashioned way.
Every time I change a screen, the screen shows the bottom of the page and then I have to use the curser to get to the top of the page. Might there be some setting that has been unknowingly changed? I'm using a Toshiba Satelite Laptop with Vista.