[AccessD] doCmd.SaveRecord not firing Form_Before_Update event

I am getting nearly work out with Access not behaving as I would expect -
and in this case, as Help tells me it should. I have a process which needs
to save an order record then create an invoice. The invoice will have
amounts for various types of fees calculated as either based on an amount
entered per bottle, or a flat amount; but if a field FeeTypeid is set to a
value such that looking up that feetypeid in the FeeType table yields a
feeType of 'N/A', I do not want the amount to be calculated (ie, should be
zero).

This determination is to be made in the Beforeupdate event.

However, upon saving the record, that event is not firing. I have verified
in the form property sheet that this event is set to fire.

Any help out there? Arrrggghghhgg!