Fb.Feed() not working in android when facebook app is installed

I installed Facebook sdk for unity. Fb.Feed() function working properly in editor & in android device also. But if facebook is installed in android device, then Fb.Feed() function is not working...Is it a bug, or I missed something...

I used exact same code as provided with example game- FriendSmash. And same problem also happening with FriendSmash game...