RhinoMocks: Correct way to mock property getter

I'm new to RhinoMocks, and trying to get a grasp on the syntax in addition to what is happening under the hood.

I have a user object, we'll call it User, which has a property called IsAdministrator. The value for IsAdministrator is evaluated via another class that checks the User's security permissions, and returns either true or false based on those permissions. I'm trying to mock this User class, and fake the return value for IsAdministrator in order to isolate some Unit Tests.

This is what I'm doing so far:

public void CreateSomethingIfUserHasAdminPermissions()
{
    User user = _mocks.StrictMock<User>();
    SetupResult.For(user.IsAdministrator).Return(true);

    // do something with my User object
} 

Now, I'm expecting that Rhino is going to 'fake' the call to the property getter, and just return true to me. Is this incorrect? Currently I'm getting an exception because of dependencies in the IsAdministrator property.

Can someone explain how I can achieve my goal here?