Interesting read http://www.jboss.com/index.html?module=bb&op=viewtopic&t=95617&am... unfortunately I still have no idea how to set this 'bad' option. One use-case the above thread seems to ignore is 10 independant completely-ignorant-of-each-other applications each with their own local-tx. Anyhow, I tried setting com.arjuna.ats.jta.allowMultipleLastResources=true in the 'jta' properties in conf/jbossjta-properties.xml (as per http://labs.jboss.com/jbosstm/docs/4.2.3/manuals/html/jta/ProgrammersGuid...) but get a org.jboss.deployment.DeploymentException: No Attribute found with name: allowMultipleLastResources exception. Am I correct in assuming local-tx-datasources implement the LastResourceCommitOptimisation marker interface ? Or am I barking up the completely wrong tree? Am I really the only person having this problem? Dave P.S. JBossTM really should not be 'deprecated'. The above thread implies it no longer exists in JBoss 5 - this is really unfair. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4053415#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...