DELETE and reuse variables

We have a COBOL program that deletes a record, moves new values into the 
key fields and then writes a new record.  The expectation was that the old
field values from the deleted recortd would be retained and the
new record would be the same data, but with new key values.

We are seeing some records where the field values from the deleted record
are not retained.  Not totally sure the COBOL program in question is the
cause, but I thought I remembered the famous IBM phrase 'results may be
unpredictable' regarding variables from deleted records.  The program
would require generous unit, system, and regression testing - along with
similar management signoffs - so I thought I would get some feedback
first.

Comments?
    

Dan Rasch - because if the human species concentrated on the really 
important things in life, there would be a shortage of fishing poles!
IBM Certified twice....... but still a couple PTFs away from Nirvana.