Try setting the scroll at 10 lines. If that doen't work then go down to 5 or 3 lines. It's probably an issue between your resolution, monitor and mouse. You can probably find a "middle ground" by playing with the settings.
2 lines is the best, that way you don't completely miss rows in Aaron's 2-line lists (such as when selecting shipsets, or looking at a sector with lots of ships)