Edit: oops... yes the mouse arrow does slow down a bit but I fixed it by setting it at the faster speed... I was adjusting the wrong setting before by accident. Silly me.... I thought i already ahd it at the fastest but I didn't.
Good to see you fixed it. Just as an FYI, the reason it is slower in a higher resolution is because there is more screen for it to move over. TECHNICALLY it is moving just as fast as it was on 800x600, but it's automatically going to be faster moving across the whole screen when the screen is 800 pixels wide than when it is 1280 pixels wide.