Forum plugin - using the forum short cut only works on draft pages/posts not on published pages/post


Just installed the Forum plugin on a WordPress 3.1 Network (multisite) install, and when trying to use it on a Networked site I can create my forum, copy the forum shortcut code and create a new post. However, if I publish the post I get a 404 error. If I preview the draft version of the post I see the forum page as expected.

Any ideas? Thanks.