Comment 2 for bug 381884

The jump happens during the context switch from one-finger pointing to two-finger pointing. The reference point changes from the location of the one finger to mid-way between the two fingers. The arrow should not move when the second finger is added or removed. That's why it scrolls, even though the user hasn't moved.

Just to be clear that it's not a problem of sensitivity. The input reference point should be reset without moving the output point, when entering and leaving two-finger mode.