It's working for me. Don't know if this would make a difference but did you Click the "Remember me" check box when you signed in? It sometimes cures strange problems. Also, try "Refresh"?
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 .