Jabber - can't add contact

I just set up Jabber and connected (using Miranda). Now I’m trying to add contacts. I can find and add contacts through the users.jabber.org directory, and I can accept an invite, but when I enter a Jabber ID to add directly it doesn’t work. So I can’t add any googletalk contacts as they’re not listed at users.jabber.org.

Btw, does anyone know the user directory hostname for googletalk? I couldn’t find it anywhere.