I completed the game on hardcore but did not receive any achievements for doing so. I go back and look at act 4, and I am missing two chapters. I completed the two chapters, and again no achievements. I go back to the dashboard, and see that my gamer points equals "0", and my gamerpic is gone. I restart my console, sign in, and my achievement points and avatar are back, but the game still states that I have not completed two chapters in act 4.
This is ridiculous, and needs to stop. Is this a known issue or something?