Access to class loader RMI

Hello,
I am writing an RMI-chat program, but I have some problems using dynamic class loading.
I do set my security manager, I've got a java.policy, use the right commandline-options, but I get the following error when I try to dynamicly load a class. The class is on the right server, and the server is running, and properly set in the codebase:
ClassNotFoundException: access to class loader denied.
Can anyone please help me?
Johanna

Sorry,
I was using two codebases, and one was not accesible in the policy file.
My bad

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