well I replaced all the files on the server with new copies I downloaded from here and then just copied over my database settings and that all seemed to go ok. The admin control panel now shows version 8.04.
The problem is the forum is still acting wierd. I still can't stay logged in for more then a minute or two. If I try to delete a post I get logged out and the post is not deleted. It seems to be a problem with the cookie, it never remembers my login anymore. Also it shows a session variable in the querystring now which it never needed before.
I also tried it on my laptop and I was having the same kind of problems. Anyone got any ideas? This is all very strange.