I am after splitting my pages on a blog in to 1/3s, then the posts to be full size, does nayone know of a plugin that WORKS...we have tried 4 and none seem to work with the new WP release.
I don't think I am understanding what exactly you want to accomplish. Could you try explaining it a bit better, or give an example of a site that already has what you want? Giving the names of the plugins you have tried that did not work would also help shed some more light on what exactly you are trying to do. If you are looking to just make a post and have the content spit up into multiple pages (posts starts on one page with navigation to the next page for more content from the same post), just put <!--nextpage--> on a line in your post where you want a page to end and a new one to begin.
I use Homepage Excerpts, available here (I don't think it's in the official plugin repository). It's a bit dated, but worked on WP 3.2.1 (haven't yet tested on WP 3.3.).