Adding a new forum section

[MLF LLC]

A little background ... I had set up a forum section for the purpose of brainstorming and development for my forum. Along with the Admin and Mods there were a select few "invited" to participate in this forum section. Back in Nov we were hacked into via the install folder still on our server.

That security issue was addressed but ever since our "invited" members have no longer been able to access our Think Tank forum section (not sure if the issue is related to the hack or not). I have since gone back and checked all the permission settings - forum section and users, to no avail. I even went so far as to delete the forum section, rebuild it and add a specific usergroup ... still no luck.

Ideally this is what I would like to do,
1. add new forum section as a sub-forum of our Admin forum
2. new forum section to be a non-public, invite only forum
3. Permissions for Admin, Mods and "invited" members only
4. "invited" members will change over time so permissions need to be able to be modified

Thanks for help in advance,
MLF