core.sys.windows.com.ComObject apparently has wrongly laid out Vtable

[Richard (Rikki) Andrew Cattermole]

Basically what you are seeing is normal C++ class behavior.

The only difference between a C++ class reference and a COM class 
reference, is that the methods in the vtable is stdcall for COM.

It's worth noting that for every class and interface in a given class 
hierarchy, each have different vtables for a given object.
This is why you must cast the D object to IUnknown first before 
inspecting its reference.

Which reflects what the compiler is doing when you inherit from 
IUnknown, set the default calling convention and convert to a C++ 
class/interface.