Customer Problem Description:
------------------------------
The JDK interceptor implementation has a bug whereby
making outcalls while unmarshalling return values won't work:

Here is my analysis for the first problem.

                    The scenario is that a client makes a request with
interceptors enabled. The
                    return value of the request is an Externalizable that
does PRO.narrow()
                    inside of its readExternal() method.

                    Here's what happens:

                    1. The request is constructed.
                    2. Interceptor starting points are invoked.
                    3. A new ClientRequestInfoImpl is pushed on the info
stack (PIORB.java:621)
                    4. The request is made.
                    5. The arguments are unmarshaled. Interceptor ending
points haven't been
                    invoked yet since the arguments are still being
unmarshaled.
                    6. readExternal() calls PRO.narrow() which eventually
calls is_a which has to
                    make a remote request (ClientDelegate.java:838)
                    7. ClientDelegate constructs a new request and calls
interceptor starting
                    points (PIORB.java:599)
                    8. Since the infoStack hasn't been popped yet the
_current_
                    ClientRequestInfoImpl is got (bad). Since we have made
the previous request
                    its replyStatus is 0 (no exception), but since the
interceptor code is
                    expecting a new Info object it blows up at PIORB.java:514.