Footer not fixed

Wonder if this is a known bug?

I have a table with <thead>, <tfoot> and <tbody>. When the page first loads, the header is fixed but the footer is not when scrolling, ie. the footer is not visible when first the page first loads up, and thereafter if scroll down and then scroll up, the footer is not visible. If I refresh the page, then footer will also become fixed and working from then on. But if I navigate to another page, then come back to the same page, again the footer is not fixed and required a refresh of the same page.

<script type="text/javascript" charset="utf-8" src="http://www.datatables.net/media/javascript/complete.min.js"></script&gt;
<script type="text/javascript" charset="utf-8" src="http://www.datatables.net/release-datatables/media/js/jquery.dataTables.js"></script&gt;
<script type="text/javascript" charset="utf-8" src="http://www.datatables.net/release-datatables/extras/FixedHeader/js/FixedHeader.js"></script&gt;
<script type="text/javascript" charset="utf-8">
$(document).ready( function () {
var element = document.getElementById('itemsTable');
new FixedHeader( element , { "bottom": true} );
} );
</script>