The Lion, The Witch and the PG rating?

We took the kids to see The Chronicles of Narnia: The Lion, the Witch and the Wardrobe this afternoon. We've all read the book, the kids and I have seen the play and we've all seen the old version of the movie. Still, we were unprepared for the level of violence shown in the PG rated flick. Nothing was left to the imagination. The stabbing of Aslan made me wince (and I've seen Natural Born Killers). So, while I thought the movie was well done, it certainly deserved a PG-13 rating. If nothing else, it would have given us a heads-up that we needed to preview and review it with our children before taking them to see it.