Richie,
if you go into Beta then into "my profile" go to bottom of page you should see "Yes, I would like to send and receive private messages" check the box and that should work
its a Q&A site. Beta has the same posts and questions as here but with avetars and a PM service that occasionally works.
this section is one section out of many that was added as many people were passing the time of day on other threads and not just answering the questions. Oh and the trolls were frequenting other sections and pushing important posts off the page rapidly
That does not make answerbank (either version) a chat program in my eyes.