I discovered a big issue with using discount codes and recurring payments. The issue is, new invoices are not being generated when using discount code on first invoice (other discount types has not been tested atm), only a transaction is created on for the same invoice. That is not right, and effectively makes the discount apply every time the subscription is renewed.
This is a big issue, that effects our bottom line. I've shared a dropbox link with you in "additional information" with a short video from our developer to show the issue.
I hope you can help fix this ASAP.