I took a look at the JNDI code and the problem wasn't there. In looking at the code, I believe the problem is that when the persistence-unit configuration which specifies the jta-data-source is processed, the datasource is looked up and stored as part of the persistence-unit information. It doesn't keep looking up the entry specified in jta-data-source. I'm now thinking that I need to do something at the datasource level. Is there something there that I can subclass to introduce my own code for getting the connection? Len View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4083704#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...