Hi Susanne,
When a document type is a Credit Note, that already takes into account the reverse debiting and crediting as does for invoices. If you enter a negative amount into the details, that acts like a 'double-negative', so that the net posting will act like an invoice. That would definitely explain why the debits and credits are not working as you expected.
Therefore, you will have to change the way you do your document processing. As you mentioned, the easiest thing might be to create a different spec for printing credit notes than you do for invoices. If you decide to go this route, you need to make sure that all amounts are entered as positive. Adagio Invoices knows how to apply the debits and credit correctly, depending on the document type.
If it is really important to see a negative sign on your printed documents, you can enter a negative Invoice (not a credit note at all). This will print the amounts as negative and perform the proper debits and credits. Note that doing this will not allow you to 'apply' this to an existing invoice.
In the Company Profile is the settings for document numbers and more specifically the 'Next' Invoice and Credit Note number. You can modify this is you wish, and also add document 'prefixes' to more easily differentiate invoices and credit notes. As long as you are running an updated version, you will be prevented from posting a duplicate number for the same customer. For those invoices and credit notes that already have been posted, these cannot be altered at all.
Regards,
Softrak Support