Armour texture selection bug?

[Niiya]

I have a chest armour mod with two different models and as a consequence two different diffuse and normal maps (despite the UV's being the same, the AO is in a different place due to the models being different) one for female and one for male.

I assigned a "material" and a "material female" to the item, as well as "mesh" and "mesh female".

However the female version is using the male material. Is there a way to do this so it uses the correct material for each version or is that some game bug?

In essence I'm asking if the "material female" modifier works and if so how to use it?