Recently I wrote an article in which I proved the following important facts.(1) For extremal inclusions of subfactors the principal graph is ergodic if and only if the dual graph is ergodic. (2) the subfactors the are resulted as limiting algebras of non-degenerate commuting squares have ergodic principal graphs. The referee rejected my article though to the counter example by U.Haagerup, but the professor denies the existence of such counter example, also I searched all over and never seen any counter examples . the proof of these claims are very short and easy. If any one knows of counter examples please let me know