I finally got the solution. The problem comes from the "Sandbox"
APNs Feedback server, probably a bug. Here is the solution if anyone
has the same problem:
Create a dummy app id in the program portal, enable development push
notifications on it Create and download the associated provisioning
profile Create a new xcode project, and invoke the
registerForRemoteNotificationTypes method on start. Install the dummy
app on your device. At this point, you should have two DEVELOPMENT
apps running on your device: the original app and the dummy app. Both
should be registered to receive push notifications. Uninstall the
original app, and try to send a push notification to that app. Invoke
the feedback service, and you should receive data back.
To resume, the Sandbox Feedbacks server needs TWO DEVELOPMENT Apps
registered on the SAME iPhone to work.
This manipulation is not necessary for the production phase as the
"Production" APNs Feedback server works fine.
Regards,
Dorian