1. Open Poser fresh to an EMPTY scene.

2. Load the full morphed version of Aiko 3 from the DAZ Aiko library.

3. Open the Pose folder for Miette and inject the head morph.

4. Apply the body MOR pose. Everything will be just as it should be.

This is very simple. There is nothing wrong with the injection pose or the body MOR pose and all work exactly as advertised to create one of the prettiest Aiko characters out there.  I'm sorry you can't seem to get it to work properly, but I asure you I and several of my best testers have wasted a good deal of time today trying to reproduce this error and we cannot. It always works perfectly. 

This character does NOT WORK with the FREE AIKO BASE. The free version of Aiko does NOT contain the required empty injection channels so the disableing script is never being applied.

The problem is likely because you are using the wrong version of Aiko.