JMX and AMQ 5.10

Hi:

I'm using AMQ 5.10 ( default settings ) and I'm trying to extract
statistics by JMX commands

I've only defined (in activemq.xml)

<managementContext>
<managementContext connectorPort="1616"
createConnector="true"/>
</managementContext>

And if I run

, I can connect to that port

But if I try to run a JMX query by cmdline-jmxclient

java -jar cmdline-jmxclient-0.10.3.jar localhost:1616
org.apache.activemq:type=Broker,brokerName=broker1,destinationType=Queue,destinationName=MYQUEUE
ConsumerCount

the process hangs , up to a timeout is thrown
And if I try to connect by jconsole, it cannot connect to it

All of this works fine if I use AMQ 5.8

What's new in 5.10 ? did I forget anything ?

Thanks and regards