incorrect unread behaviour of global annoucements

There is a incorrect behavior of the unread status of global announcements (3.0.1-RC1).
These are the steps I took which describe the problem and how to reproduce it:
[list: 2cbm1riy]

• User A posts a global announcement and a reply to an existing topic
• User B logs in, goes to the forum with the unread reply. Both the normal topic as well as the global announcement are marked unread.
• User B reads the new reply by clicking the "View first unread post" link on viewforum.php
• User B clicks on "Return to Your first forum" after having read the reply
• Back on viewforum.php, the global announcement is now marked read, although it has not been read by User B.