Without looking at your code it's difficult to diagnose what is going on. The log message | 2007-02-27 11:58:51,891 INFO [org.jboss.resource.connectionmanager.NoTxConnectionManager] Unregiste | red handle that was not registered! null for managedConnection: de.chs.siebel.jca.SiebelManagedConne | ction@65ab77 | Is telling you that according to the ConnectionListener, the handle is unknown. Being that you are having issues with the close, the first place I would check is in how you are handling the association of ConnectionListeners in your code. Something is preventing this association from happening. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4023099#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...