Hi there, I think you have to make JBOSS use SimpleReadWriteEJBLock instead of the default PessimisticQueueLock, by including the following block in jboss.xml: <container-configuration extends="Standard CMP 2.x EntityBean"> | <container-name>Standard CMP 2.x EntityBean</container-name> <locking-policy>org.jboss.ejb.plugins.lock.SimpleReadWriteEJBLock</locking-policy> | </container-configuration> This is what I did, and it did not give me any more transaction locking errors, but I do find this approach slower, it seems to load all the data from a table instead of just pulling the required row for me... I just posted a query on this forum about this and hope someone can help me with that :) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3973445#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...