Moderator queue does not display icon if the new post is made in old thread

Currently, when new posts needs approval (first post approval feature) there is a small icon displayed in the forum index alerting moderators about the queue.

This function works (icon is displayed) on my site if the new post is a new topic, but it doesn't show if it was made as a reply to old thread.
-> You need to go to MCP to get notified if the topic is out of sight in page 2 and above.

Discussion in QA forums
http://www.phpbb.com/community/viewtopic.php?f=95&t=2094158#p12804211