I was having the same problem and got an email response from my support ticket basically saying there isn't a problem. Funny, how it magicially went away without me doing anything.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .