Usergroup permission issue

[ScottC20]

OK this is the problem I am currently experiencing:

I have the following usergroups in use:
Registered Users - Regular members
Subscribers - people who pay a fee using the subscription feature and get access to a hidden forum and extra PM space etc...
Bog Members - A publically joinable usergroup for threads of a more adult nature.

Now it seems that people cannot be subscribers AND Bog Members at the same time -whilst I can set their Primary Usergroup to Bog Members, and Subscribers as an additional Usergroup, it appears they cannot receive both benefits. i.e. if Subscribers is the primary usergroup they cannot see the Bog Members hidden forum, and vice-versa.

Is there any way around this? Some way to set an 'order of precedence' for the usergroups? How can I set Bog Members to become the primary usergroup automatically upon someone joining?

[Jake Bunce]

That should work. But the primary group(s) in question must have this option enabled:

Admin CP -> Usergroups -> Usergroup Manager -> Edit Usergroup -> Allow Users to have Member Groups

Otherwise the secondary group will not affect permissions.