Cannot use "IgnoreCall" on an overloaded private m

Hi,
I am using TypeMock Isolator 5.3 for mocking out private methods in my unit test. At a higher-level, calling "IgnoreCall" on a particular definition of a method that has multiple definitions does not work. TypeMock acts as if there is no "IgnoreCall" specified for that method.

Let me dive into a little bit of detail here -

Lets say I am unit-testing the following class:

public ClassA {
...
...

private static Sum(int x, int y){
    --- implementation ---
}

private static Sum(Inputs inputs){
    Sum(inputs.x, inputs.y)
}
...
...

}

The goal is here to verify that Sum(x, y) is called with inputs.x & inputs.y when I call Sum(inputs).

So my unit-test code looks somewhat like this -

[Test, Isolated]
public void Test_Sum_WithInputs() {

   Isolate.NonPublic.WhenCalled(typeof(ClassA), "Sum").WithGenericArguments(typeof(int), typeof(int)).IgnoreCall();
   Inputs inputs = new Inputs(2, 3);

   // Use reflection to call the private static method
   typeof(ClassA).RunStaticMethod("Sum", inputs);


   Isolate.Verify.NonPublic.WasCalled(typeof(ClassA), "Sum").WithArguments(2, 3);
}

What happens when I run the test with above code?

TypeMock complains about some missing dependency in the method Sum(int x, int y). But I asked it to Ignore it, instead it would call it.

Is there a different way of unit-testing situations like this? Am I doing something wrong here?

Essentially I am trying to learn how TypeMock isolator behaves when I am dealing with overloaded methods irrespective of whether a public method is calling a public method or a private method or any other combination you can think of.

Any inputs are greatly appreciated,
Thanks,
Sudhir