[Magento 1.9.1] Generates two invoices

[Pookster]

I'm setting up a store with downloadable products. When an order is placed, two invoices are created. One with the actual price and one invoice with a price of zero. I assume this is not correct.

I don't know wether this has to do with each other, but the order conformation mail is also sent twice to the customer.

Any help is very appreciated

[Magician_Dhara]

Are you using any third party extension to send Emails? And I would suggest you to verify your cron job setting in cpanel as well. Let me know for further help.