Currently when in the message center, the same message can be marked as "unread" multiple times consecutively. On the home screen, the message center notification will increment with each marking and will only decrement once for each time the message is marked "read."
1) Find a message in any of the messages folders
2) Mark as unread.
3) Check the home tab's message notification, it should have properly incremented.
4) Go to the same message and mark as unread again.
5) Return to the home tab and notice that the notification for new mail has incremented again, suggesting an additional email when there is not one.
To undo the process, the message must be marked as read for each time it was marked unread.