应用程序打开Url方法在用户认证Facebook之后未调用

我已将ios应用程式中的Facebook升级到3.0，并使用 https://developers.facebook.com/docs/howtos/login-with-facebook-using-ios-sdk/ 通过Facebook登录用户，但问题是用户允许Facebook访问 - （BOOL）应用程序：（UIApplication *）应用程序
openURL：（NSURL *）url
sourceApplication：（NSString *）sourceApplication
注释：（id）注释方法未被调用。但有趣的是，当我创建一个新的应用程序并在该应用程序中集成相同的代码时，同样的方法被调用在那里。我使用的是xcode 4.4。任何建议为什么会发生在我现有的代码。

I have upgraded the facebook in my ios app to 3.0 and using the code provided at https://developers.facebook.com/docs/howtos/login-with-facebook-using-ios-sdk/ for user login through facebook , but the problem is that the after the user allows the facebook access the - (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation method is not being called. But the interesting part is that when i create a new application and integrate the same code in that application the same method is being called there.I am using xcode 4.4. Any suggestion why is it happening with my existing code.