....
    // References the currently running request or null if no request is active
    this._currentRequest = null;
    // Running transports array
    this._transports = new Array();
    this._timeoutPage = "";

....

    _sendStandalone : function( request ) {
      // [if] Dispose the last transport before creating the new one
      // see bug 301261
      for (var i = 0; i < this._transports.length; i++){
    	  var transport = this._transports[i];
    	  var state = transport.getState();
	      if( transport != null && 
	    		  state != "configured" &&
	    		  state != "sending" &&
	    		  state != "receiving") {
	    	transport.getRequest().dispose();
	    	transport.dispose();
	    	this._transports.splice(i, 1);
	      }
      }
      // TODO [rh] WORKAROUND
      //      we would need two requestQueues (one for 'normal' requests that
      //      is limited to 1 concurrent request and one for the 'independant'
      //      requests created here
      //      Until qooxdoo supports multiple requestQueues we create and
      //      send this kind of request without knownledge of the request queue
      var vRequest = request;
      var vTransport = new qx.io.remote.Exchange(vRequest);
      // Establish event connection between qx.io.remote.Exchange instance and
      // qx.io.remote.Request
      vTransport.addEventListener("sending", vRequest._onsending, vRequest);
      vTransport.addEventListener("receiving", vRequest._onreceiving, vRequest);
      vTransport.addEventListener("completed", vRequest._oncompleted, vRequest);
      vTransport.addEventListener("aborted", vRequest._onaborted, vRequest);
      vTransport.addEventListener("timeout", vRequest._ontimeout, vRequest);
      vTransport.addEventListener("failed", vRequest._onfailed, vRequest);
      vTransport._start = (new Date).valueOf();
      this._transports.push(vTransport);
      vTransport.send();
      // END WORKAROUND
    },