 				
 				progress.addEventListener(Event.OPEN, function() : void {
 					start = new Date;
+					try {
 					_conn.load(request);
+					} catch (ex:*) {
+						onIOError({
+							type: IOErrorEvent.IO_ERROR,
+							target: _conn
+						});
+					}
 				});
 				
 				_conn.addEventListener(Event.COMPLETE, function(e:Event) : void {

		private function onStatus(e:HTTPStatusEvent) : void {
			_status = e.status;
		}
		
		private function onIOError(e:IOErrorEvent) : void {
			if (_status == 0) { // httpStatus might have already set status to some failure code (according to livedocs)
				_status = 404; // assume that request succeeded, but url was wrong
			}

			onOpen(); // trigger it manually
						
			_readyState = XMLHttpRequest.LOADING;
			try {
				_conn.upload(request, _blobFieldName, false);
			} catch (ex:*) {
				onIOError({
					type: IOErrorEvent.IO_ERROR,
					target: _conn
				});
			}
		}
		
		
