[jQuery] form plugin and blockUI problems in IE7 with the ui not unblocking

[jQuery] form plugin and blockUI problems in IE7 with the ui not unblocking


I'm using the form plugin and the most recent version of blockUI.
Here's my form initialization area:
        $(document).ready(function() {
         var options = {
         target: '#search_results', // target element(s) to
be updated with server response
         beforeSubmit: showRequest, // pre-submit callback
         success: showResponse // post-submit callback
         };
         // bind to the form's submit event
         $('#search_form').submit(function() {
                $.blockUI();
         $(this).ajaxSubmit(options);
         return false;
         });
        });
And then here is my post submit callback function
        // post-submit callback
        function showResponse(responseText, statusText) {
            // add sorter.
            $("#myTable").tablesorter({sortList:[[0,0],[2,1]], widgets:
['zebra']});
            $("#options").tablesorter({sortList: [[0,0]], headers: { 3:{sorter:
false}, 4:{sorter: false}}});
            // add pager.
            $("#myTable").tablesorterPager({container: $("#pager")});
            $("#pager").show();
            $.unblockUI();
        }
All this works ok in Firefox but in IE, blockUI does not unblock. I
don't get any javascript errors and it seems like the call should go
through ok. Any ideas?
Thanks,