In my code (see below), I make an AJAX call. Firebug tells me "Error: Bad http response code: 0" and the page reloads. If I step through the code, it works, i.e. no errors, and then the page reloads. The server-side code is returning only headers and Apache is returning a 200 return code.

1. Why is my page reloading?
2. Any suggestions on tracking down this heisenbug?

function sendFNDdata(pressedBtn) {
   var myresponse;
   var vargetFNDdata = {
   url: "cgi-bin/PortSim/getFNDdata.pl",
   handleAs: "text",
   content: { value: pressedBtn },
   timeout: 5000, // Time in milliseconds
   form:dojo.byId("fndParms"),
   load: function(response, ioArgs) {
             myresponse = response;
             alert('YES!');
             dojo.byId("cargo").innerHTML = response;
             return response;
          },

   error: function(response, ioArgs) {
             myresponse = response;
             console.error("HTTP status code: ", ioArgs.xhr.status);
             return response;
          }
  };

  dojo.xhrGet(vargetFNDdata);

  return myresponse;
};

which is called by

   Output Files