Refresing jquery dialog content not working

Refresing jquery dialog content not working

I have the below code for launching a dialog and refreshing it with an image and time stamp every minute. The initial load works fine however on the refreshes the time stamp changes but the image doesn't. I have the cache setting as false and the image file returns with the cache headers set to expire in the past. So I'm a little stuck seems to happen in all browsers. Any advise would be appreciated

  var div = $('<div id="'+id+'"><div id="wait"><img src="images/loading/ajax-loader_teal.gif"></img></div>').dialog({
            modal: false,
            open: function ()
            {
        $('#wait').show();
        $.ajax({
              url: 'GetImageData.php?sid=' + id,
              cache: false, success : function (data) {$('div.html').empty(); div.html(data);}}
        );
            },
            height: 300,
            width: 400,
        position: { my: "center", at: "center", of: window },
            title: dtitle
        });
    vectors3RefreshId = setInterval(function(){$.ajax({
                                                url : "GetImageData.php?sid=" + id,
                                                cache: false,
                                                success : function (data) {
                                                    $(id+'.html').empty();
                                                    div.html(data);
                                                }
                                            });
                                        },60000)
    },
    featureunselected: function() {
    //Stop the refresh of the stop dialog
    clearInterval(vectors3RefreshId);
    }
   
});