The spec requires pass-by-copy semantics for invocations through the Remote view. If you don't need location transparency the best approach would be to switch to a Local view. That will work as long as the caller and callee are in the same application.
We do have an option to force pass-by-reference semantics for Remote invocations, but it has the same limitation that the caller and callee be in the same application. To use that, set the target bean's pass-by-reference flag to true in sun-ejb-jar.xml.
[Message sent by forum member 'ksak' (ksak)]
http://forums.java.net/jive/thread.jspa?messageID=280178