The screen on my ThinkPad Edge sometimes zooms in and out when I run my finger along the Touchpad or when I tap on the surface. I know you can use the "pinch" with two fingers to zoom in and out but this happens to my set with just a tap of one finger.
How can I adjust the Zoom settings for my E520?
In Control Panel go to Mouse -> UltraNav -> TouchPad Settings -> Application Gestures -> Pinch Zoom -> uncheck the Enable Pinch Zoom box.
You can also adjust other settings to your satisfaction here.