Why disabling cache doesn't work?

Why disabling cache doesn't work?

Here is my script

<script src="../../Scripts/jquery-1.4.1.js" type="text/javascript"></script>
<script type="text/javascript">
        jQuery.ajaxSetup({
            // Disable caching of AJAX responses 
            cache: false
        });

        jQuery("#button1").click(function (e) {
            window.setInterval(refreshResult, 3000);
        });

        function refreshResult()
        {
            //alert("In refreshResult");
            jQuery("#divResult").load("/Home/Refresh");
        }
</script>

It updates part of a web page every 3 sec. It works only once after clearing web browser cache, after that requests are made to /Home/Refresh without interval of 3 seconds and nothing is displayed on the web page.
I am using ASP.net MVC 2 and c#.

I would be grateful for an answer.