This week's book giveaway is in the Reactive Progamming forum. We're giving away four copies of Reactive Streams in Java: Concurrency with RxJava, Reactor, and Akka Streams and have Adam Davis on-line! See this thread for details.
Are you asking about http://code.google.com/p/jforum2/ or about http://jforum.net/ ? They have different code bases. Furthermore, it's impossible to tell what might be going on without knowing what code is being executed when this problem occurs. So: what are you trying to do, and what output do you see in the various log files? There should be more information in one of them.
A feeble attempt to tell you about our stuff that makes us money