Asyncoperation.progress stucks on 0.9 ?


I am using, asyncoperation to load scenec faster.
When i debug the progree by using asyncoperation.progress , it will stuck on 0.9 always.
Please help me about that.

Here is the code.

using UnityEngine;
using System.Collections;

public class StartScreenGUI : MonoBehaviour {
	private AsyncOperation asyncOpe;

	void Start(){
		asyncOpe = Application.LoadLevelAsync( "Play" );
		asyncOpe.allowSceneActivation = false;

	void Update(){
		if( asyncOpe.isDone == true ){
			Debug.Log(" progress = " +asyncOpe.progress);

i believe it wont actually finish if the allowSceneActivation is false it will stop at 0.9