Issue scrolling with fixed position

Issue scrolling with fixed position

I am having trouble with the scrolling when I use a position:fixed inside
of another position:fixed. The simplest way to demonstrate this issue is
with this fiddle:
http://jsfiddle.net/xDDJb/
I want to be able to scroll with the mousewheel while having the mouse
over the smaller fixed div. I have to keep .wrapper the way it is (aka I
cannot remove the position:fixed).
The context is that I'm using Bootstrap 3 modals and I want to essentially
create this layout in the modal. The BS .modal class uses position: fixed
and creates the same construct as the example's .wrapper.
I would love any suggestions please!