smoothAnchors.js not working in IE

smoothAnchors.js not working in IE

I'm having trouble getting smoothAnchors.js to work in IE. Can anybody see
where I'm going wrong please?
I am using bigvideo.js on this page
http://thewebsitedeveloper.co.nz/thinkRedTest/sureFire/index.html and also
have a button activating a scrolling animation to a div using
smoothAnchors.js
The scrolling animation works perfectly in all browsers on my local host,
and on the test site it works fine on all browsers except IE where the
scrolling animation is not working. it does work when I turn off
bigvideo.js. Can anybody suggest a way to make this work with the video?
Any help greatly appreciated. Thanks in advance.
HTML
<div class="arrowButton" id="scrollIt">
<a href="#lower-content">
<img src="images/arrowDown2.png" alt="down pointing arrow icon">
</a>
</div>
jQuery
<script>
$(function() {
var BV = new $.BigVideo();
BV.init();
BV.show('video/surefireRedBg.mp4',{ambient:true});
//scrolling to anchor links
$.smoothAnchors("slow");
});
</script>