When updating A/P batches, why do some payment batches report an error?

The error message (that arises when the user cannot update the batches) in the Work Centre reads:

Batch 350298 K in error

Payment 0 0 in Error

Record Invalid

In the message body:

Subject: Record Invalid

"CAUSE ...the record being processed either already exists for an 'ADD' function or does not exist for an 'INQUIRY', 'CHANGE' or 'DELETE' function.

RESOLUTION ... If you are attempting to inquire, change or delete a record you previously added, there may be database problems in your production library. You should notify your data processing department."

My brief research revealed the following:

In the payment batches that are in error, the table F0911 does not contain corresponding records, even though the batch records can be found in F0011, F04013 and (via the payment ID field) in F04014.