The segfault must have been due to something I inadvertently introduced into my configuration while trying to set up irssi-plugin-xmpp.
After cleaning up my configuration and running /xmppconnect, I was able to establish a successful connection and all is working. I know I should have saved the old configuration file, since a segfault isn't desirable even with invalid configuration settings. -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

