I (http://moodle.org/user/view.php?id=18237&course=1) was receive a message from Richard Bright (http://moodle.org/message/discussion.php?id=626655).
Before I was able to read this message account of Richard Bright was deleted.
Now in list of people who send me a message present mr. Bright but I can't read his message so it can't be hided from list and this list constantly popup.
I didn't try block all messages from mr. Bright yet.