This has been bothering me for a few days now. When I view a topic that is new or has recent responses and then go back to the forum, the topic is still marked as "new". Blocking cookies and clearing cookies between sessions don't help at all so it may be browser-related...

Is anyone else having this problem, or is it just me? And are there any known fixes?

This happens on the nanosite as well in the regional forum sections. It has to do with caching. It happens on the three browsers I have tried.

Apollo16

There is a 15 minute site cache; for that approximate amount of time, the server will not refresh your topic list. It's a design feature to reduce strain on the database server (and hopefully keep the sites up and running.)