when a topic is visited (not get replied) the updated field is updated to the current datetime, and the topics is ordered by updated, so the topic will be shown on top, this should be changed to when a topic is replied the updated field is changed to current datetime.

my simple patch, there should be better patch I think

The problem comes with the signal thing. When a topic is visited, post.views = F('views') + 1, then post.save() will fire the trigger of topic_save() signal, and this will bring a huge performance problem when every topic is clicked. So a better patch should be considered.

Tnx, i will review this problem soon.
Maybe better move recount logic from signals to save()