Comment 1 for bug 666051

Well, IMHO the category of product, this generate the right account.move, with demo data:

Debtors (value) at credit vs Product Sales ( value) at debit choosing the account partner as do it module now we get the bug and check the code onchange methods are called what update the account.invoice.line, To use POS i assume the accountant people get configured categories and action_invoice will create correctly the invoice.

regards,