Cannot bind Proxy to JNDI Context in WL9/10

We are in the process of upgrading from WebLogic 8 to WebLogic 9.2 (or 10) and
have come across an error.  We have a series of Remote Interfaces that we expose
for RMI calls. We wrap the remote implementations in a proxy and bind the proxy,
which allows us to perform work before and after the transaction.  While this
all worked in WebLogic 8/JVM1.4, upon upgrading to WL9/JVM1.5 we get the
following error:

java.lang.ClassCastException: $Proxy73
        at
weblogic.rmi.extensions.server.ServerHelper.replaceAndResolveRemoteOb
ject(ServerHelper.java:417)
        at
weblogic.jndi.internal.WLEventContextImpl.copyObject(WLEventContextIm
pl.java:377)
        at
weblogic.jndi.internal.WLEventContextImpl.bind(WLEventContextImpl.jav
a:276)
        at javax.naming.InitialContext.bind(InitialContext.java:359)^M
        at
com.cox.webdev.csapi.InterfaceBroker.bindAll(InterfaceBroker.java:164
)
        at
com.cox.webdev.csapi.app.CsapiApplication.configureInterfaces(CsapiAp
plication.java:481)

How do we get around this issue?  Binding the implementation works, but we lose
a lot of our security and statistics layer.

The proxy is created through:
      RemoteInterfaceInvocationHandler handler =
         new RemoteInterfaceInvocationHandler( imp );

      Object prox =
         Proxy.newProxyInstance(
                                 imp.getClass().getClassLoader(),
                                 imp.getClass().getInterfaces(),