Don't try the second way; you shouldn't edit the conf/jndi.properties file.
Can you enable TRACE logging for org.jnp and post what happens before the exception?
View the original post :
http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4155462#...
Reply to the post :
http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...