Problem with cost estimate

Dear CO Experts,

when ever i run cost estimate system should only expolde the bom for FG material only and suould not explode bom for the semifinished goods.It should take only consider sfg cost according to the price control in the material master. To do this i deactivate with quantity structure tick for all SFG.

But when i run a costestimate for SFG system should explod the bom and calculate newprice based on bom qty and rm prices.

when i run ck11n and ck24 for individual materials the above said process is working fine.now the problem is when i run ck40n for all the materials i can only update the price for FG only.All the SFG prices are not getting updated.

pls provide me solution to this problem

regards,

siva