You cannot create a listener on dynmic queue.
You have to create static queue and set listener on that. Dynamic replyToQueue is fine. You can easily support 10 clients. Also Do you have multiple instance of server?
Please see the information from sun documentation:
"Like a stateless session bean, a message-driven bean can have many interchangeable instances running at the same time. The container can pool these instances to allow streams of messages to be processed concurrently. The container attempts to deliver messages in chronological order when it does not impair the concurrency of message processing, but no guarantees are made as to the exact order in which messages are delivered to the instances of the message-driven bean class. Because concurrency can affect the order in which messages are delivered,
you should write your applications to handle messages that arrive out of sequence. "
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