Error in scheduling.

In AX4.0 ,

When I try to schedule a batch order (production order) then I get following error:-

"Cannot edit a record in Net requirements (ReqTrans).
The record has never been selected."

Setting used in the scheduling tab:-

Scheduling direction:-Forward from Today

Finite capacity=YES

Finite Material=YES.

(If I remove the"Finite Material" at the time of sheduling then there is know error.)

This error is only for one item.Other items batch orders are scheduled correctly with above setup.

My Understanding of Finite material=YES is …schedule the order only if the matreials awailable for that particula order.

But even if there is no stock of a rawmaterial & I usee “Finite material” still system does the scheduling for other items.

For the item having error throws above error even if all raw materials are available in stock.

Any hint …why this item is behavinf differently ?