Dear,
Please check the following
1.Goto SAP T-code OPK4 -Define Confirmation parameters - with Order Type and plant-Goto General valid settings -Maintain Parial Confirmation and the un-check box for the post open reservation .If you mark this box , then FI indicaor will be st automatically at Production Order Final Confirmation .
2.Also chekc in Co11n , if ytou do not mark Clear Open Reservation option , then FI indicator will not be set in MIGO or any material posting .
3.In OPK0 , define confirmaiton screen -select SAP001- Hit in dfault area , if you mark this , then in co11n screen it will come automatically .So flag off the same in OPK0
Hope this helps