I am using bootstrap-datepicker. The datepicker works, but looks like this:

Only the datepicker is affected. Other elements (buttons, labels, etc.) appear with standard bootstrap formatting. This is the case on both my local server and on IE 9.
I am not changing any of the datepicker's parameters or doing anything fancy:
$(function () {
$("#datepicker").datepicker();
});
Full jsFiddle here: http://jsfiddle.net/4KbV6/1/