Hi, I just checked opened a a defect in activemq as discussed with david jencks on IRC. This deals with Mdbs stopping processing if the instance limit is < maxSessions. The defect is https://issues.apache.org/activemq/browse/AMQ-1618. It is present in all the versions of AMQ. I have also explained and tried out the fix that David suggested and it works absolutely fine
Regards Manu