I've managed to fix it, but I don't understand how! I mentioned before that application 2 on machine 2 contained a jndi.properties (to allow it to talk to machine 1). When I renamed this to application2.properties, the problem was solved. I can only assume that this jndi.properties in application 2 was preventing the ejbs in application 1 from making themselves available to JNDI. I don't quite understand why this should be. I could understand if application 1 wanted to do an outward JNDI lookup and read the jndi.properties in application 2 by mistake. But I don't understand why it should affect inward JNDI. If anyone is able to explain why a jndi.properties should have this kind of effect, I'd be interested to find out - but I'm just grateful it's fixed. Thanks Jaikiran for your help. Heather View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4113023#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...