Chris,
I think I have the same problem.
I have download the new version 3.10.04 and installed on a DNN 3.1.1 version.
After installing, I have added some groups with some forums.
Now I have set in the General settings of the forum the Authorized Edit Roles to registered users, but a registered user do not have write access to the forum (the buttons new thread, my setting and my posts are not visible).
I have then tried to set the edit permission for registered users in the modules setting, and then the registered users are able to post new threads and so on.