Seems like the RID gets incremented once too many (outside of upper bound of expected window), and then server responds with item-not-found. See: http://xmpp.org/extensions/xep-0124.html
@@ -4592,8 +4592,6 @@
sid = this.session.get('sid');
jid = this.session.get('jid');
if (rid && jid && sid) {
- // We have the necessary tokens for resuming a session
- rid += 1;
this.session.save({rid: rid}); // The RID needs to be increased with each request.
this.connection.attach(jid, sid, rid, this.onConnect);
} else if (this.prebind) {