after you deploy the MDB can you check if there is a message consumer is active for queueB, you should be able to do this through the WSMQ administration
Since your outbound (EJB to queue) is working , there should be no problem with your generic ra configuration, what is the connector resource (connector connection pool) used by the EJB, does it also use the "sowu_connection_factory_mn1p" as the Jndi name (snippet from domain.xml would help)
Refer to
https://genericjmsra.dev.java.net/docs/websphere-mq-integration-guide/webspheremq_integration_guide.html
for a sample deployment descriptor, i guess you dont need the mdb-connection-factory and you have to correct your jndi-name .
-Ramesh
[Message sent by forum member 'rampsarathy' (ramesh.parthasarathy_at_sun.com)]
http://forums.java.net/jive/thread.jspa?messageID=368789