Status: Minor and not always repeatable.
1) Click on 'Show new replies to your posts' and read the messages until only one message thread is left in the list.
2) Click the box on the far right of the message thread to ignore the topic, a click appears in the box.
3) Click on 'IGNORE TOPICS'.
4) Sometimes a very old topic now appears in the list which has not been replied to for months if not years.
Note that this bug does NOT trigger if you start off with only one item in the list.