On my MacBook Pro i have realised that the default mouse cursor (black arrow) has its hotspot a few pixels off the top left corner. It becomes obvious if I move the cursor slowly to a button in the browser. While the tip of the arrow is already like 3 or 4 pixels in the button it does not highlight it yet. When I move it one pixel further the cursor turns to the hand cursor and the tip of the finger is exactly on the edge of the button.
Is this on purpose? Can I change that somewhere?