asyncRequest, YUI 2.7, status=404 not understandable behaviour

Question

hi, I'm using YUI to talk to server on Grails framework. Using asyncRequest, I successfully passed a parameter to my server and have the server println the result.

However, the callback function still insists "not found" on the statusText.

Could some one enlighten me on what might be wrong with my code?

thanks!

  var deleteCallback = {
                success: function (o) {
                if (o.responseText == 'Ok') {
                   alert('following records deleted:' + deleteList);
                  } else {
                   alert('too bad');
                   //alert(o.responseText);
                  }
              },
              failure: function (o) {
                 //alert('this is a failure!');
                 alert(o.statusText);
              },
             scope:this
                };
          YAHOO.util.Connect.asyncRequest(
            'GET',
             '/controller/action/deleteRow?deleteList=' + deleteList,
             deleteCallback
          );