AS3 URLLoader POST aborted in browser - actionscript-3

Question

I've re-built an SWF audio uploader, and it was working fine for a few days. However, I just did a run-through of all the things I've built onto this project, and I notice that the POST request to the server to save the audio file is being Aborted about 10 seconds into the request. At 20 seconds, everything stops because of a timeout limitation that is implemented. I don't know much about AS3 or how it makes requests, but I do know that the PHP handler file is solid because no changes were made to it from the point which it worked last. The permissions are 755 and ownerships are correct on both the SWF and the handler file. I can also re-submit the request via Firebug, and it works with no issue whatsoever.
I'm not sure where the problem is stemming from exactly; whether it be browser, server or code issue. I was reading about Aborted requests and I've ensured that there are no other active requests before trying to upload. I should also add that other POST/GET requests have no issues, it's just this one request from the SWF.
Again, Flash/ActionScript is not a strength of mine, so if there are ways to improve what I'm doing, or if anyone can tell me what I'm doing wrong, please tell me.
package{
import flash.display.Sprite;
import flash.media.Microphone;
import flash.system.Security;
import org.bytearray.micrecorder.*;
import org.bytearray.micrecorder.events.RecordingEvent;
import org.bytearray.micrecorder.encoder.WaveEncoder;
import flash.events.MouseEvent;
import flash.events.Event;
import flash.events.ActivityEvent;
import fl.transitions.Tween;
import fl.transitions.easing.Strong;
import flash.net.FileReference;
import flash.net.URLLoader;
import flash.net.URLRequest;
import flash.net.URLRequestMethod;
import flash.display.LoaderInfo;
import flash.external.ExternalInterface;
import flash.media.Sound;
import org.as3wavsound.WavSound;
import org.as3wavsound.WavSoundChannel;
import com.adobe.serialization.json.JSON;
import com.adobe.serialization.json.JSONDecoder;
public class Main extends Sprite{
private var mic:Microphone;
private var requestor:URLLoader;
private var waveEncoder:WaveEncoder = new WaveEncoder();
private var recorder:MicRecorder = new MicRecorder(waveEncoder);
private var recBar:RecBar = new RecBar();
private var maxTime:Number = 30;
private var tween:Tween;
private var fileReference:FileReference = new FileReference();
private var tts:WavSound;
public function Main():void{
trace('recoding');
recButton.visible = false;
activity.visible = false ;
godText.visible = false;
recBar.visible = false;
mic = Microphone.getMicrophone();
mic.setSilenceLevel(5);
mic.gain = 50;
mic.setLoopBack(false);
mic.setUseEchoSuppression(true);
Security.showSettings("2");
requestor = new URLLoader();
addListeners();
}
private function addListeners():void{
recorder.addEventListener(RecordingEvent.RECORDING, recording);
recorder.addEventListener(Event.COMPLETE, recordComplete);
activity.addEventListener(Event.ENTER_FRAME, updateMeter);
//accept call from javascript to start recording
ExternalInterface.addCallback("startRecording", startRecording);
ExternalInterface.addCallback("stopRecording", stopRecording);
ExternalInterface.addCallback("sendFileToServer", sendFileToServer);
}
//external java script function call to start record
public function startRecording(max_time):void{
maxTime = max_time;
if(mic != null){
recorder.record();
ExternalInterface.call("$.audioRec.callback_started_recording");
}else{
ExternalInterface.call("$.audioRec.callback_error_recording", 0);
}
}
//external javascript function to trigger stop recording
public function stopRecording():void{
recorder.stop();
mic.setLoopBack(false);
ExternalInterface.call("$.audioRec.callback_stopped_recording");
}
public function sendFileToServer():void{
finalize_recording();
}
public function stopPreview():void{
//no function is currently available;
}
private function updateMeter(e:Event):void{
ExternalInterface.call("$.audioRec.callback_activityLevel", mic.activityLevel);
}
private function recording(e:RecordingEvent):void{
var currentTime:int = Math.floor(e.time / 1000);
ExternalInterface.call("$.audioRec.callback_activityTime", String(currentTime));
if(currentTime == maxTime ){
stopRecording();
}
}
private function recordComplete(e:Event):void{
preview_recording();
}
private function preview_recording():void{
tts = new WavSound(recorder.output);
tts.play();
ExternalInterface.call("$.audioRec.callback_started_preview");
}
//function send data to server
private function finalize_recording():void{
var _var1:String= '';
var globalParam = LoaderInfo(this.root.loaderInfo).parameters;
for(var element:String in globalParam){
if(element == 'host'){
_var1 = globalParam[element];
}
}
ExternalInterface.call("$.audioRec.callback_finished_recording");
if(_var1 != ''){
ExternalInterface.call("$.audioRec.callback_started_sending");
var req:URLRequest = new URLRequest(_var1);
req.contentType = 'application/octet-stream';
req.method = URLRequestMethod.POST;
req.data = recorder.output;
requestor.addEventListener(Event.COMPLETE, requestCompleteHandler);
requestor.load(req);
}
}
private function requestCompleteHandler(event:Event){
ExternalInterface.call("$.audioRec.callback_finished_sending", requestor.data);
}
private function getFlashVars():Object{
return Object(LoaderInfo(this.loaderInfo).parameters);
}
}
}