People posting to / viewing wall despite security settings disallowing that

I set up a Friends list called Restricted, which has been set up to see or do barely anything, including not being allowed to post to my wall and not see my status updates and not see 99% of my applications, and yet one of those people has added comments to the wall. It's not working as configured. All I really want that person to do is to send messages to my Inbox, but nothing public. By the time you read this I will have deleted that person's comments, but I want to ensure that it doesn't happen again, and they really can't see what I've written.

It's a real security problem, because information is out there which I have purposely restricted, and apparently people can post to my wall despite me saying they are restricted from doing that.

This urgently needs fixing.