Touchpad scroll gesture does not trigger mousewheel event in IE.

Hello,

When developing a web app for Windows 8.1, I noticed that the Surface Touchpad does not fire and mousewheel event when using the two-finger scroll gesture. The expected behavior is that using the touchpad's scroll gesture would simulate the same event as using a mouse's scroll wheel.

A proof of concept for this bug can be found here:

http://jsfiddle.net/dontsteponme/57tascmg/3/

Thanks.