Costing of a non-stocked item in a BOM

Hi Guru's

We are on ECC 5.0. I am having issues when costing assemblies that consume materials created with Item category 'N - Non-stocked items' in BOM.

As an example, Material A is an assembly that consumes a raw material B that is purchased from a vendor. I don't stock raw material B but as and when required to make material A, I will purchase it from the vendor. So I created the BOM for material A with material B in it as a item category 'N'. I am costing material A and it does not pull all the cost components (i.e raw material costs on material B, freight charge from purchasing material B). All it does is shows up a value with out cost component splits.

But on the flip side, if I create the BOM for material A with material B as a stocked item (Item category L), costing of material A is showing all cost components perfectly.

Is there any configuration that I need to do to retrieve cost components when costing assemblies that contain non-stocked items.

Any input is really helpful.

Thanks,

MG