JBoss 5.1 GA, JBoss Messaging 1.4.3 GA (comes with JBoss 5.1GA)
JBoss ESB 4.6
Windows x64 with the 64 bit version of the jvm (1.6)
We have a strange condition where sometimes a message will be placed in the queue by the esb but a JMS client local to the machine (so no firewall in between) will not be able to read the message placed in the queue. We do not see any exceptions in the server log (it is in DEBUG for the org.jboss classes). New messages placed in the queue will be readable by the the client until another message will be placed in the queue that has this kind of property (that makes it not readable) and this continues like that.