Using a COM Interop object but for one fake method

I am using Typemock Isolater version 5.4.5.0 with Visual Studio 2005.

I have a COM object accessed through COM Interop and an interop assembly that I want to use in my testing, but I need to fake one method/property.

When I execute the following:


DMFlowtableSheetClass _fakeSheet = Isolate.Fake.Instance<DMFlowtableSheetClass>();
Isolate.WhenCalled<string>(
delegate(string s)
{
return _fakeSheet.get_SubFlowtables(s);
}
).AndArgumentsMatch((Func<string>)
delegate
{
return true;
}
).WillReturn(null);

“fakeSheet.get_SubFlowtables(s)” in the WhenCalled delegate calls the actual object regardless of what I specify for the Members enum on the call to Isolate.Fake.Instance. I’ve tried passing in Members.ReturnRecursiveFakes, but it still calls’ the original method.

In all cases I want to call the original method/properties, except when calling get_SubFlowtables.

How do I make this work?