the problem is caused by conflicting version of jquery on the page.
near the top of the head section, you include jquery version 1.9.1
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
then further down you include version 1.4.2:
<script src="http://code.jquery.com/jquery-1.4.2.min.js" type="text/javascript"></script>
<script type="text/javascript">
var currentYear = (new Date).getFullYear();
$(document).ready(function() {
$("#year").text( (new Date).getFullYear() );
});
</script>
those 2 are causing a conflict, causing the accordion to fail.