There's a few people who constantly edit there posts.

Some do it to add a bit to a post, or to edit grammar or spelling.  They tend to do it only for newer posts.  Not really an issue, although I do find it a little irritating for 'x new' posts to show up on a forum when the content is the same.  I do this at times, although I try to write things correctly the first time so I don't have to go back.  If it's a minor mistake it bugs me, but if there's at least one post after mine I try to ignore it.