Turning off custom errors in Windows Service

Question

I have a Windows Service that uses .NET Remoting (yes I know remoting has been replaced by WCF but this is a legacy application).

When I run the service I get this:

Exception Type: System.Runtime.Remoting.RemotingException Message: Server encountered an internal error. For more information, turn off customErrors in the server's .config file.

I have this in my application's config file:

<configuration>
    <system.runtime.remoting>
        <!-- other settings go here -->
        <customErrors mode="Off" />
    </system.runtime.remoting>
</configuration>

Oddly, I still get this exception. What am I doing wrong?