For people with the rubberband mouse issue I have found a way that will actually solve this problem with out constantly holding down the right button while playing.
What u do is once u get in to the game click on new quest, any character than okay. Once the opening movie start playing press "Esc" immediately and this will take u straight in to the game play. From that moment on the mouse should working normally, even when u exit back to the main menu or play some instant action games.
Hopes this will help.
However, I find the music of the game seem bit off sync with the game play, for example some time when I play instant action I will get the Main Menu them and no sound effect .