I unchecked the auto-enter "calculated value" box that enabled the calculation: If (Customer_option = "self" ; Product1Id ; self ). Basically my layout has a radio button with the option "self", which if selected auto-enters one field to another on the same layout, with both fields belonging to the same table. The layout is in a different context than the table of both fields. Unchecking the calc box has eliminated the auto-enter as expected, but it thankfully appears not to have erased historical data. I want to restore the calculation without erasing historical records. Should I check the " do not replace existing value of field" box? Seems obvious, but given i havent lost data so far Im wondering if FM is out-smarting me again.