xhr响应：连接已关闭

I wrote a Flickr search engine that makes a call to either a public feed or a FlickrApi depending on a selected drop down box. examples of the JSONP function calls that are returned:

a) jsonFlickrApi({"photos":{"page":1, "pages":201, "perpage":100, "total":"20042", "photo":[{"id":"5101738723"...

b) jsonFlickrFeed({ "title": "Recent Uploads tagged red","link": "http://www.flickr.com/photos/tags/red/","description": "", ....

the strange thing is that in my local install (xampp) both work fine and i get images back BUT when i host the exact same code on the above domain then the jsonFlickrApi doesn't work. What i notice (by looking at Firebug) is that for the jsonFlickrApi the response Header says Connection close

Also, Firebug doesn't show me a Response tab when i submit a request to the jsonFlickrApi

here is the code:

function makeCall(uri)
{
    xmlhttp = new XMLHttpRequest();
    xmlhttp.onreadystatechange = callback;
    xmlhttp.open("GET", "jsonget.php?url="+uri, true);
    xmlhttp.send();
}

function jsonFlickrApi(response)
{ 
  var data= response.photos.photo ;
  var output = "";
  output += "<img src=http://farm" + data[4].farm + ".static.flickr.com/" + data[1].server + "/" + data[4].id + "_" + data[4].secret + ".jpg>";
  document.getElementById("cell-0").innerHTML = output ;
}

//Public Feed
function jsonFlickrFeed(response)
{
  var data= response.items[0].media.m ;
  alert(data);
  var output = "";
  output += "<img src=" + data+ ">";
  document.getElementById("cell-0").innerHTML = output ;
}

function callback()
{
    //console.log("Ready State: " + xmlhttp.readyState + "
Status" + xmlhttp.status);
    if(xmlhttp.readyState==4 && xmlhttp.status==200)
    {
                var jsonResponse = xmlhttp.responseText; 
        jsonResponse = eval(jsonResponse);
    }
}

examples of calls:

a)

http://flickr.com/services/rest/?method=flickr.photos.search&api_key=75564008a468bf8a284dc94bbd176dd8&tags=red&content_type=1&is_getty=true&text=red&format=json&timestamp=1339189838017

b)

http://api.flickr.com/services/feeds/photos_public.gne?tags=red&format=json&timestamp=1339190039407

Question: why does my connection close? why is it working on localhost and not on the actual domain?