IE ajax基本身份验证

I am using ajax to upload an xml file, the POST includes the Basic Authorization Header (see below) works fine on all browsers but not IE. It seems IE will not send the Authorization Header with the ajax post. Please note this is not Cross Domain. I know there are other similar question on this subject but I cannot get a solution to make an ajax post with Basic Authorization on IE (9+10)?

         $.ajax({
            type: "POST",
            beforeSend: function (xhr) {
                    var basic = $.base64.encode(username+":"+password);
                    xhr.setRequestHeader("Authorization", "Basic " + basic);
                    xhr.setRequestHeader("X-Verbose", "true");
                    xhr.setRequestHeader("X-Packaging", "http://eprints.org/ep2/data/2.0");
            },
            url: url,
            data: payload,
            contentType: 'text/xml',
            processData: false,
            success: function (msg) {
                    payload = "";
            },
            error: function (jqXHR, textStatus, errorThrown) {
                    alert('Error Message: ' + textStatus);
                    alert('HTTP Error: ' + errorThrown);
                    alert(errorThrown.stack);
            }