Why do MDBs use transacted sessions?

[inders1]

Hi:
1.) MDBs on JBoss are setup to use transacted sessions, always. The following lines in JMSContainerInvoker actually do that:

// set up the server session pool
 pool = createSessionPool(tConnection,
 minPoolSize,
 maxPoolSize,
 keepAlive,
 true, // tx
 acknowledgeMode,
 new MessageListenerImpl(this));

2.) If I were to make the "transacted" parameter to false, will it hae any undesirable effects on the rest of the application, if the application is not interested in dealing with transacted sessions.

We are running JBoss 3.x and 4.x against a ConisMQ server.

I tried finding information on this topic on this forum, but couldnot get much information - so all help is appreaciated.

-Thanks.
-Inder.