Issues with Public permissions

Hello,

I've got some weird issues with public permissions on my site.

I want to restrict a special area to just allow everyone to access and read topics, but only allowing to post / create new threads after registration / login.

To be more clear - what i would like to do is:
Access / Read Topics -> allowed for everyone
Create / Post Replies -> disabled for public, but allowed for my "lowest" group "Rookie" (which is automaticaly set after registration) and everything above

So, i went to Settings -> General and activated "dedicated permissions"
For my concerning forum, i also checked "enable permissions" with "YES"

Permissions are set as following:
Display / Access -> "Allowed" for every single group
Create New Topics -> "Not Set" for public, "Allowed" for all other groups
Post Replies -> "Not Set" for public, "Allowed" for all other groups
Read / View Topic -> "Allowed" for every single groups

Having it activated as above, it doensn't matter if i'm logged in or not, creating a topic and posting is possible for everyone (even after logging in and out to reset session).

If i change my permissions for create / replie topics for my group "rookie" to "not set", suddenly creating / replying is restricted for both "public" and this "rookie" group.

So, maybe someone got an idea here?
Thanks in advance!

Hi anewtry,

This is a fresh forum installation or you already had the forums and you are trying to make a change to one of the forum sections ?

Best regards,
Max