[flexcoders] FDS Messaging error

[Robs]

Hi all,
  I'm trying out a sample chat app using fds messaging. As per the 
instructions, I made a new destination in the messaging-config.xml as 
follows:

<destination id="MyTransientTopic">
        <properties>
            <server>
                <durable>false</durable>
            </server>
        </properties>
        <channels>
            <channel ref="my-rtmp"/>
        </channels>
</destination>

Unfortunately, my application does not seem to get this destination & 
is throwing the following error:

[Error: (mx.messaging.messages::ErrorMessage)#0
  body = (null)
  clientId = (null)
  correlationId = "AC6C8425-5819-7952-C465-DBB44D54B08E"
  destination = "MyTransientTopic"
  extendedData = (null)
  faultCode = "Server.Processing"
  faultDetail = (null)
  faultString = "No destination 'MyTransientTopic' exists in service 
flex.messaging.services.MessageService"
  headers = (Object)#1
  messageId = "996330F1-2418-1987-0B1E-A4C224645BD9"
  rootCause = (null)
  timestamp = 1176212098404
  timeToLive = 0]


  Where am I going wrong? Please help !

Regards,
Robi.