I think we are talking apples and oranges here.
If a record is truly a new record, there should not be any values associated with any fields. So I would expect that the Remaining debt, Total Payments, and Total fields to ALL be empty/null (if it is a new record, where exactly are these other field values coming from)?
I suspect that you are either using some sort of LOOKUP function, or some sort of calculated running total on these other two fields, and I was hoping you would be able to tell what exactly what it is.
However, did you try what I suggested in the previous post?
Instead of trying to use the DEFAULT value, try replacing the Control Source for that field with that formula.
Note that you may need to qualify the field with the Query name (whatever that is), i.e.
Code:
=NZ([QueryName].[Total Payments],0)+0
If you are still running into trouble, it may be helpful if you can upload a copy of the database (removing and sensitive data first), and let us know which Form you are looking at.
I cannot download it from my current location, but can from home later tonight.