Updating Frozen Cost to Zero

Hello,

We are trying to change the current parts from their current amount to zero.  I am able to change the simulate to zero , but when I run the Cost Roll program (R30835) the zero does not move into Frozen or the Cost Ledger (F4105).  I can change simulate and roll the cost to other values but when I try to change it to zero it doesn't work.  Anyone with a reason why this happens .....Thanks!!!