Strange error with Release Strategy

Hi,

I have configured Class FRG_EKKO in CL02 to look at 4 Characteristics: 1) Amount 2) Document Type 3) Material Group and 4) Plant.

When I create PO with an Item that belongs to F2000 Material group, it gets Release strategy Z5 correctly.

However, when I add another item that belongs to F3000 Material group, but same plant, it takes out Release Strategy. When I check, it says 'Purchase document not subject to relase strategy'.

Where should I check now and make sure it retains Release Strategy ?

Niranjan