Problem with Payment Voucher (Advanced Layouts)

Hi all

We are moving to advanced layouts and are trying to replicate the payment voucher PDF. In the old style PDF forms, the payment column shows the total applied as part of the payment transaction: this would include the amount applied to a credit, and the amount applied to the invoice by the payment. However the advanced pdf forms show a payment value after credits have been applied.

For example: I have an invoice for £100, and a credit for £25. When a payment is made to cover both the credit and the invoice, the old style pdf layout will list the credit with a payment amount of -£25 and the Invoice with a payment amount of £100. The total of this is the correct payment amount of £75. However, the advanced PDF layout payment voucher will list the invoice with a payment value of £75 and the credit with a payment value of £25. The payment voucher total amount will still say £75, but the sum of