[jQuery] blockUI not closing in IE

[jQuery] blockUI not closing in IE


I recently implemented the blockUI plugin to enable a modal image
popup on a site. I have since encountered an issue unblocking the
modal image element in IE6 and IE7. I have tried several methods of
restructure the code, but all still seem to fail. The image displayed
as the modal element is removed, but the modal border is still present
and the background is still blocked.
<script type="text/javascript" src="jquery.blockUI.js"></script>
<script type="text/javascript">
<!--
$(document).ready(function() {
    $('.Content').before('<img id="overlay" style="display:none;"
src="image.gif" border="0" alt="" />');
    jQuery.blockUI({
        message: $('#overlay'),
        css: {
            top: (jQuery(window).height() - 500) /2 + 'px',
            left: (jQuery(window).width() - 500) /2 + 'px',
            width: '500px'
        }
    });
    $('#overlay').click(jQuery.unblockUI);
});
// -->
</script>
Could this be conflicting presentational css? Please could someone
help me out here.