Assigning a different Category set with a new Item Category to a new OU

Hi

We have several companies using inventory module and we now have to use inventory module for a new OU.

As we were already using inventory module the Inventory Category Set is already in use; we are using the default Inventory Item category.

I defined and new Inv Item Category as we need more segment for this new OU..., I also defined a new Category set with this new INV Item Category, however when i create an item in the new OU, I still see the default item category already selected for this item, the new Category setcan be selected in the LOV but it is not defaulted.