PHP response not recieved back by Flash

Question

I have this really weird problem. I'm making several calls to different php files (located on another server with crossdomain.xml changed so that it is allowed) and need to receive some response back in flash and work with the data received.
The first call is done by the following code:
ActionScript Code:
var urlRequest:URLRequest = new URLRequest("http://otherserver.com/assign.php");
var loader2:URLLoader = new URLLoader();
function selectHandler(event:Event):void
    urlRequest.method = URLRequestMethod.GET;
    urlRequest.data = "";
    loader2.addEventListener(Event.COMPLETE, serverResponse);
    loader2.load(urlRequest);
function serverResponse(e:Event):void {
    serverNum =  e.target.data.toString();      // gets server numbers
    registerAndUpload();
This call works fine. I receive back the event data and can store it in serverNum. 
After this when the user presses another button I call the following code:
ActionScript Code:
var requestModify:URLRequest;
function completeHandler(evt:Event) {
                            // get link to modified image
    returnString = evt.target.data.toString();   
    newURL = "http://api"+serverNum+".otherserver.com/api/img/"+returnString+".jpg";
                            //put new img into right frame
    imgAfter.source = newURL;
btnModify.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownModify);
function mouseDownModify(event:MouseEvent):void{
    requestModify = new URLRequest("http://api"+serverNum+".otherserver.com/api/modify.php?");
    var Modify:URLVariables = new URLVariables();
    Modify.id = tempArray[0];
    Modify.coords = tempArray[1]+","+tempArray[2]+","+tempArray[3]+","+tempArray[4];
    Modify.nose = txtNose.text;
    Modify.forehead = txtForehead.text;
    Modify.weight = txtWeight.text;
    Modify.tan = txtTan.text;
    Modify.eyedef = txtEyedef.text;
    Modify.key = "test-05a671c66aefea124cc08b76ea6d30bb";
    //ADD ABOVE AS DATA TO URLREQUEST
    requestModify.data = Modify;
    requestModify.method = URLRequestMethod.GET;
    loaderRequest.dataFormat = URLLoaderDataFormat.VARIABLES;
    loaderRequest.addEventListener(Event.COMPLETE, completeHandler);
    loaderRequest.load(requestModify);
After the button is pressed and the php call is made, the completeHandler function is never called. But when I test it in Firefox (I have Firebug installed), it shows me that the call is made i.e: 
http://api0.otherserver.com/api/modify.php?........
yet the completeHandler function is never executed. Any thoughts?

Answer 1

Where is loaderRequest set up?
In any case, take the URL that Firebug showed and open that in a new browser window. Does it succeed?