Compatibility with Recurring Payments Addon

The Fastbill plugin fires its action whenever a payment was marked as completed. So it should be no problem using recurring payments as well I assume.

It does NOT work with recurring payments. The first payment worked – the second didnt. At least on my site. Where can I find support for this plugin?
And even worse: After the first payment, the user was able to get the fastbill-invoice from his backend. After the second, the link is gone.
There is only one row with the information that it has been billed 2 times. Instead of one row for each payment.