What version of JBoss are you using?
There is a bug in 3.0.4 that is fixed in 3.0.6 that causes the kind of behavior you describe.
Tried with jboss 3.0.6 and it still doesn't work. Can you send more information? Do you have the bug number?
I don't have a bug number handy.
The 'patch' was made in
org.jnp.interfaces.NamingContext.java in the
public Object lookup (Name name)