Sensitivity not triggering

[bacoords]

The sensitivity option has no effect on any browser I've tested on. I'm wondering if this has to do with the fact that we're using the mouseleave event on HTML? If it only fires when the mouse has already left how are we able to increase sensitivity? Or possible I am misunderstanding the meaning of the sensitivity option.

I was able to fix this by using the 'mousemove' event (and keeping track of clientY so that I could ensure the mouse is moving generally upwards and not downward).