the problem is twofold:
1. you are being impatient
2. you are closing chat when you look at other topics
we don't all just sit around and chat, and the few of us that are usually on just idle in there using an IRC client (like mIRC, Miranda IM, xChat, whatever works)
so when you see people in there, say something, and wait a while, if you want to talk.
just chill. keep it open in a tab while you browse, and check in on it now and again. if no one says anything and you've already said hi, continue to just browse through TBT/do whatever else you're doing at the comp, if you still want to chat with whoever's on (or want to wait and see who comes on)
the biggest problem with the chat is impatience, and using the browser-client (which only shows what people have said since you've joined, not everything that's been said previously)