Paypal automatic complete order

Hi there. I'm testing out the "Download items" feature and using Paypal's sandbox for testing. It works great but it looks like I'm doing something wrong somewhere. The Paypal goes through and the testcustomer get an email telling that the order is done. But the testcustomer can not download the download items. - I had to go in as administrator and manually set the order to "Complete". Then the testcustomer was able to start the downloading. What can I do to get this done automatic?

Edit: Still testing. The order stops in "Pending" (even that Paypal has done the transaction).

1. Be sure that the "Completed" paypal status is the same thing you set for the "Download Status" in the main System Settings
2. Verify paypal is completing the order verification step by enabling "Debug mode" in the Paypal settings. Then when you checkout with paypal, you should see the messaging being logged to the system-> error log. Check for something like
PP_Standard: IPN -> VERIFIED

Thank you. I will try this out later and give an feedback when I'm done.