Ok thanks, that makes a bit more sense. You basically have 3 options: a)Use the javax.transaction.UserTransaction interface to demarcate transaction boundaries in your Servlet. Doing this will enable you to remove the explicit commits from your code, as well as use the default transaction isolation level of the driver. b)Manage the transactions explicitly yourself. This is effectively what you are doing now, just with the wrong datasource, <local-tx-datasource>. This is why it worked when you switched to the <no-tx-datasource>. c)Wrap your POJO's in an EJB and allow the container to manage the transactions for you. Generally I prefer the first approach because it keeps your POJO's free of transaction code that can be cumbersome to read, and error prone. Further, try to leverage as much of the application server facilities as you can, that's why it is there. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3965480#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...