Minor Description
If a client sends a Stomp frame without a priority header, the broker does not set the message priority to the default value (4) which is specified in the JMS spec (see http://download.oracle.com/javaee/1.4/api/javax/jms/Message.html: DEFAULT_PRIORITY The message producer's default priority is 4.)
As effect, the message will have priority 0 (lowest).
Adding a priority header for all messages by the Stomp client, even for default priority, would also cause larger messages to be sent over the wire.