I think I have the same issue as well. So far I have only messed with paypal sandbox… so that might be it, but it seems like it should work. I go through to test the process. everything seems to goes fine. But when returned to the site it says “no payments received.” I later get an email with
Sandbox Instant Payment Notification – Failure
An instant payment notification was received but not posted!
The purchaser email gets registration and payment notifications.
