A few things:
http://obstacleracers.com.au/news/forums/ - all good
However, if I try and create a topic through the Word Press dashboard as the administrator it works just fine.
If I straight to the forum front end and try post from there whilst logged in as Mr Administrator, it does not create a topic and just goes back to the front page.
Also, if I log out and go to the My Profile section and hit Register it says that "User registration is currently not allowed."
Like I said, I am dumb...