Class override not working

So the code used is the 'load_platform_subclass' code in
lib/ansible/module_common.py

get_platform just calls the python:

    return platform.system()

You might wish to debug and see if that is being reported as AIX?

Found the problem. Made a copy and paste mistake so class definition was AIX(object) in stead of AIX(User).
Works fine now!