Although IE6 is not supported by SP2010 I don't want to eliminate all the IE6 users from my webpart. This webpart is calling a Siebel webservice with data regarding the current loggedin user.

While developing in IE7 everything was perfect (both FF and IE worked like a charm, but IE6 didn't show a single result, but also no errors)

It seemed that the XML traversing did not work in IE6, after using my favourite search engine I found this wonderfull script that would help solve my issue very efficient!

    var DataUtilities = (function() {
    //Privileged variables and methods
    var self = {
    "processXML": function(xml) {
    if (!jQuery.support.htmlSerialize) {
    //If IE 6+
    var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.loadXML(xml);
    xml = xmlDoc;
    }
    return xml;
    }
    };
    return self;
    })();

it is very easy to use

var xml = DataUtilities.processXML(xData.responseText);

After adding this little fix it worked like a charm again!