in an internet browser web page, not a full screen window?
If so then it is likely normal behaviour. Using the arrow keys on the keyboard is always more jerky than pulling the scrollbar up or down with the mouse.
Mine is a Desktop with Win 7 but it was the same with all other Desktops and laptops I have had.
There are no fine tuner controls for the arrow keys that there are for mouse actions.
Hoping someone can help cause I can't figure this out but I have a Gateway laptop and here's what it's doing:
When I use the arrow keys to scroll up and down the screen movement is very jerky. If I use the mousepad on the computer I can scroll smoothly. This only happens when using IE.
Oddly enough...I have an HP desktop that does the same thing when using the arrow keys...AND....when using the scroll wheel on the mouse. On that computer, if I position the cursor over the scroll bars using the mouse it will scroll smoothly.