we had this question re: Harry Potter and our DD (then 4) - and i do think the multiple pre-readings really helped her. also, the fact that we were safely at home was working for us; contrary to being in a theatre, she knew we could stop at any time. ultimately it all went very smoothly - she literally didn't break a sweat across the 8 films. she wept bitter tears when Sirius died, but Gary Oldman... hee - what can i say, the kid has taste!
but that said, i'll second HK (as usual!) on the pre-screening... it's so easy to be surprised - and it also helps prep you for things that are handled differently than the books.
