i am proud to say that i can't help as I haven't seen the Harry Potter film in question,
i know and love the books and after seeing the first film I refused to see any others so as not to damage my enjoyment of the books with the discrepancies in the films and the not realistic enough imagery
my Dad made the big mistake of trying to make me watch the second film, he hasn't done that again since the ranting it induced, they just aren't accurate enough
just my opinion tho, i know films are never as good as the books they are based on but in this case it makes me irrationally angry (as does the portrayal of Faramir in lord of the rings film)
sorry for going off on a tangent