Hmmm, interesting . . . I might have to find those.![]()
It's mostly things like "jumper" being changed to "sweater", or "Minister for Magic" being changed to "Minister of Magic". I seem to recall her putting her foot down on the changes in the later books so that the publishing companies wouldn't change quite as much as they did in the earlier books. (Though it's been a while since I've been immersed in Potter fandom..)
Edit: A good reference for the differences, http://hp-lexicon.info/about/books/differences.html.