Double invoice for same order error

Question

I have a weird problem with a small amount of my orders where there are 2 invoices being created for the same order.

There seems to be no correlation between the orders this is happening to. Different payment systems etc.

First of all, how should I resolve this in the admin section? Should I just create a credit memo for the order so 1 invoice is begin cancelled? I think this would mess up the stock count etc?

Second, any idea what might be causing this? Might I have configured the preferences wrong somewhere?

Extra information: I am using Magento 1.7 and am using the MultiSafepay - Gateways - 2.0.2 module. The option to automatically generate an invoice after payment has been ACTIVATED.

Answer 1

To resolve this in the admin just make credit memos of the duplicate invoices and make sure to fill out 0 as the quantity to return to stock.

As to debugging this: found out who is creating these invoices. It's probably some Payment Service Provider or payment module so start by adding some logging in that module or contacting the company that gave you the module