Ok, thanks for clearing that up! I've also just noticed something else. With single finger tap set to left click if I try and perform a double tap to do something like select text it does not work. I have to tap three times in order to get the same effect as a double tap. If I move a window by double tapping the title bar then after moving try to expand the window by double tapping it does not work. I have to tap three times.
Do you have any ideas why this might be happening?