Why RMI registry is ignoring the java.rmi.server.codebase property

I am running a Hello World example for java RMI

1) I run the registry in an empty folder

motta@motta-laptop ~/tmp $ rmiregistry

2) I start the HTTP server to retrieve the classes at runtime. The download folder contains the remote interface for the client-server

motta@motta-laptop ~/download $ java NanoHTTPD 8080

3) I start the server passing the java.rmi.server.codebase property as suggested in the java RMI tutorial

motta@motta-laptop ~/server $ java -Djava.rmi.server.codebase="http://localhost:8080" WarehouseServer

The RMI registry is not contacting the HTTP server and is throwing an exception (see details after the question). But if I do the following

1) Start the rmi registry with the java.rmi.server.codebase property

motta@motta-laptop ~/tmp $ rmiregistry -J-Djava.rmi.server.codebase="http://localhost:8080/"

2) Start the HTTP server as before

3) Start the server without any option

motta@motta-laptop ~/server $ java WarehouseServer

it works, but why? It seems that with the first procedure the RMI registry is ignoring the java.rmi.server.codebase property

Thank you

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I am running

java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)

The exception from the RMI registry

Constructing server implementation...
Binding server implementation to registry...
Exception in thread "main" java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
java.lang.ClassNotFoundException: Warehouse
at sun.rmi.server.UnicastServerRef.oldDispatch(Unicast