There appears to be a glitch for some users, which means that when viewing a topic from "top down", ie, oldest first, newest at the bottom, the newest posts aren't appearing as a "page 2" isn't being generated.
I can't fathom out why, so I have posted a question to phpbb to try and figure this out.
Meantime, as a workaround if you visit your preferences at ucp.php?i=prefs&mode=view you can select the options so they show as below, and this will put the newest post at the TOP of the thread. Apologies if that is confusing at first if you're used to top-down (I prefer newest at top, you might do too!).
Hope this helps until we work out a fix.

