When a forum contains announcement or sticky topics and topic cache is enabled, new normal topics disappear when created and existing normal topics disappear when updated.
addTopic(Topic topic) in net.jforum.repository.TopicRepository adds a new topic to the cache only if it's an announcement or sticky topic or if the cache contains another normal topic. Otherwise the new topic is not added. When an existing topic is updated addTopic is called too and the existing topic is removed and then never added if the above conditions are not met. [originally posted on jforum.net by peko]