Error when adding tab in child window.

Error when adding tab in child window.


Hi guys, running into a problem after upgrading.  My app launches in a new window with tabs, and then adds different tabs on load depending on a few things.  It works fine in old version, but new version is causing a JS error on laod.  Strange thing is if I refresh window, the screen loads fine. 
 
Tracked the error down to (line 4792 ish):
  1.     ajaxSettings: {
            url: location.href,
            global: true,
            type: "GET",
            contentType: "application/x-www-form-urlencoded",
            processData: true,
            async: true,
            /*
            timeout: 0,
            data: null,
            username: null,
            password: null,
            traditional: false,
            */
            // Create the request object; Microsoft failed to properly
            // implement the XMLHttpRequest in IE7 (can't request local files),
            // so we use the ActiveXObject when it is available
            // This function can be overriden by calling jQuery.ajaxSetup
            xhr: window.XMLHttpRequest && (window.location.protocol !== "file:" || !window.ActiveXObject) ?
                function() {
                    try {
                        return new window.XMLHttpRequest(); <- *** THIS LINE ***
                    } catch(e) {}           
                } :
                function() {
                    try {
                        return new window.ActiveXObject("Microsoft.XMLHTTP");
                    } catch(e) {}
                },
            accepts: {
                xml: "application/xml, text/xml",
                html: "text/html",
                script: "text/javascript, application/javascript",
                json: "application/json, text/javascript",
                text: "text/plain",
                _default: "*/*"
            }
        }, 




































      If I replace the code with the old version from 1.3, it works fine...
    1.         xhr:function(){
                  return window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();
              },

    2. Any thoughts as to the problem?  I dont like hacking the core UI library to fix it, if anyone can suggest a proper fix, it would be greatly appreciated.