As noted below in the post about Jim Thorpe we changed the default setting for Display topics from previous: from a default of all topics to 7 days. And, this was done to reduce bandwidth.

This means in Flat View that only topics posted within the last 7 days will show up even if there have been new posts made to topics older than 7 days.

In Thread View it also means only topics posted within the last 7 days will show up, even if there have been new posts made to the topic. In Thread View those topics will be on a back page regardless of what the default Display topics from previous: setting is, because new posts in Thread View don't cause the topic to float to the top as is the case in Flat View.

Perhaps 7 days was too short a period, and I think a month is too long, so maybe the happy medium it 2 weeks. Regardless, in both Flat View and Thread View you can easily change the default setting to several intervals up to and including all topics, which means you can see all topics regardless of age.

Or, you can use the View posts since last visit link which will show all posts since the last visit, also regardless of the age of the original topic.

And for you people who still miss Webbbs, and say this wouldn't be a problem in Webbbs, you're right. This wasn't a problem in Webbbs because phpbb is better. It floats the topics with new posts up to the top which Webbbs didn't (couldn't) do. And, this problem is showing up because we are attempting to reduce the bandwidth, and in doing so somewhat impacting one of the nice new features of phpbb.

But again, you can easily get around this issue by manually changing the default Display topics from previous: setting using the drop down table that the top of the forum, and/or using the View posts since last visit feature.