Could anybody tell me how to configure a client and server remote object with WindowsXP ServicePack 2 installed?

client configuration file is present here:

<configuration>
    <system.runtime.remoting>
        <application>
        <client>
        <wellknown
            type="ChatCoordinator, ChatCoordinator"
            url="http://localhost:9999/Chat"
        />
        </client>
        <channels>
        <channel
            ref="http"
            port="0"
        />
        </channels>
        </application>
    </system.runtime.remoting>
</configuration>

and here is the server configuration file:

<configuration>
    <system.runtime.remoting>
        <application>
        <service>
            <wellknown
                mode="Singleton"
                type="ChatCoordinator, ChatCoordinator"
                objectUri="Chat"
            />
        </service>
        <channels>
        <channel
            ref="http"
            port="9999"
        />
        </channels>
    </application>
    </system.runtime.remoting>
</configuration>

The client has to send and receive messages to the server by http channel using delegates.

When I start the server channel registration application with his configuration file

shown above it seems to be fine.
When I start the client it generates the following exception when trying to subscribe

for the event:
Type System.DelegateSerializationHolder and the types derived from it
(such as System.DelegateSerializationHolder) are not permitted to be
deserialized at this security level...

I want to emphasize on the installed WinXP SP2.

Can anybody fix the client and server configuration files shown above and tell me why

I can't configure the remoting object.
I have read by the forums that the reason might be unspecified

System.Runtime.Serialization.Formatters.TypeFilter Level.Full formater but I have tried and it still get the same error. May be I wouldn't written right, I don't know, this was not a syntax error.

Please publish me the complete config files!
Thanks!