Hi,
I am using JBoss 4.0 SP1.
I deployed a MDB that is not transacted.
In the ejb-jar.xml the trans-attribute tag of the MDB has the value NotSopported, like so:
<assembly-descriptor>
 <container-transaction>
 <method>
 <ejb-name>MyMDB</ejb-name>
 <method-name>onMessage</method-name>
 </method>
 <trans-attribute>NotSupported</trans-attribute>
 </container-transaction>
 </assembly-descriptor>
However, the ServerSessions that JBoss create are transacted, and the JMS sessions that they hold are transacted. As a result, after the MDB's onMessage() method is called, JBoss invokes the commit() method of the JMS session. 
Can anyone explain why non-transacted MDBs use transacted sessions? In other words, why does JBoss create transacted ServerSessions even when the MDB is not marked as transacted? 
Thanks, 
Shai