non-working IE8 AJAX success. ajaxSubmit plugin: http://jquery.malsup.com/form/#getting-started

gistfile1.js

$('#jdugc_upload_form').on('submit', function(event) {
        event.preventDefault();
        $('.loading-icon').show();

        $(this).ajaxSubmit({
            target: 'myResultsDiv',
            type: 'post',
            dataType: 'json',
            start: function(){
                $('.loading-icon').show();
            },
            success: function( msg ){
                if ( $('#jdg_upload_target_1 img').length == 0 ){
                    $('#jdg_upload_target_1').html( '<img src="'+msg.url+'"/>' );
                } else if ( $('#jdg_upload_target_2 img').length == 0 ){
                    $('#jdg_upload_target_2').html( '<img src="'+msg.url+'"/>' );
                } else if ( $('#jdg_upload_target_3 img').length == 0 ){
                    $('#jdg_upload_target_3').html( '<img src="'+msg.url+'"/>' );
                }
                $('#jdgugc_attachment_ids').val( $('#jdgugc_attachment_ids').val() + ',' + msg.attachment_id );
                document.getElementById('jdugc_upload_form').reset();
                $('#fb_photo_url').val("");
                $('#jdugc_dialog').dialog('close');

                $('.loading-icon').hide();
            }
        });
        return false;
    });