Profile Comments non-member

For some reason, non-members are able to post profile comments.

Admin>Membership Levels>Manage Membership Types>Non-member>Membership Actions>No actions allowed for this membership

I don't want non-members to be able to post. Any idea how to correct this or why non-members can post even though no action is set?

This is my problem

yes ,answer plz.

It seems this may be the only option without a mod. I found this but haven't tried it:

http://www.expertzzz.com/Downloadz/view/5193