Push notifications not working but return status says it does

I successfuly managed to make push notifications (tile and toast) work on my device. But after a few days, it's not working anymore. However I get a good return status :

array(3) { ["X-SubscriptionStatus"]=> string(6) "Active" ["X-NotificationStatus"]=> string(8) "Received" ["X-DeviceConnectionStatus"]=>开发者_运维问答; string(9) "Connected" } 

I tried to put the device in airplane mode, with no wifi, and I get

array(3) { ["X-SubscriptionStatus"]=> string(6) "Active" ["X-NotificationStatus"]=> string(8) "Received" ["X-DeviceConnectionStatus"]=> string(16) "TempDisconnected" } 

So it's "kind of" working, right ? How come I don't see any notifications ? How can I debug further ?

I have heard a lot of people having similar problems. Sometimes a Factory reset of the device seems to work, but the error often returns (especially after a reboot).

Is it working on the emulator?

The Windows Phone team blog talks about it:

http://windowsteamblog.com/windows_phone/b/wpdev/archive/2011/02/17/push-notification-status.aspx