This is the reason I haven't tried chat, taken from the general forum rules:
16. You must post on the forum at least five (5) times daily to be able to remain in the chat room. The forum is the foundation of this site, chat is just an add-on. If you don't participate on the forum, you will not be welcome in chat.
I do post on TN when I have something to add, but I don't keep the pace of 5 posts a day, every day, so I figured I wouldn't be allowed to use chat. Maybe that has relaxed now?