JEP85 support is not cached
Chat state notifications should be preferred over message events.
If Gajim receives JEP85 extensions and JEP22 extensions in a subsequent message, it will use JEP22 (message events) instead of JEP85 (chat states notifications). It should remember the client has JEP85 support and use it.
A full example has been posted to the jdev ML: <http://mail.jabber.org/pipermail/jdev/2006-November/024558.html>