I'm not sure if you've changed anything on your staging in the last 3 hours, but the problems I'm observing are related to this problem
IE doesn't support relative paths in the base element when referencing CSS files
When your page requests http://stage.change4cancer.org/profile/647955793, it gets actual html for the page. Now whether or not it's supposed to redirect to #profile/647955793 is another matter (why you'd want to do that after you've already loaded the content, I'm not sure), but let me explain.
In that html from http://stage.change4cancer.org/profile/647955793 you have the following tag:
<base href="/" />
But IE9 will not respect that tag unless it has a full URI. Therefore, all the paths to the JS, CSS, etc are wrong. Instead of
http://stage.change4cancer.org/js/libs/backbone-0.9.2.min.js
it's requesting
http://stage.change4cancer.org/profile/js/libs/backbone-0.9.2.min.js
Which actually returns yet another html page of some sort
Since none of of your external JS is loading, of course things are going to go wrong.