How to setup a paid subscriber forum that is also joinable?
 

Our forum has several classes of paid subscriptions and we have a group of forums setup that only they can see. We also have a group of forums open to all members but that is only joinable by subscribing to the forum group. Now I have been asked to setup a new forum which can only be accessed by paid subscribers and which also must be seen by joining it.

We have tried every configuration we can see of making this new forum joinable but cannot get it right. What is happening is that although the forum does not appear in the forum listings as it would be expected, a non qualifying member can still access it from a link or a bookmark and not be denied access due to permissions and is able to view, post and start threads. I hope that makes sense.

Is there any way to setup a usergroup that is joinable but that also will carry through on forum permissions?

Thanks for any assistance.