See http://area51.phpbb.com/phpBB/viewtopic.php?f=81&t=45727

Steps to reproduce:
1) Pick a topic with new posts (the new posts must be on a page with posts you have already read)
2) Click on the topic title
3) If the topic is only 1 page, it will jump to the new posts (it should go to the first post)
4) If the topic spans multiple pages, it will jump to the first post in the topic (expected behavior). Clicking on the last page (again, with posts that you have already read) will jump to the new posts (unexpected behavior - it should jump to the first post for that page).

If you need a screen video, let me know and I'll create one tonight or tomorrow and upload it somewhere.