ITunes asks for a password, but payQueue is empty

I see some strange things with iTunes and in-app purchases, both on iOS 6 (iPad 3) and iOS 7 (iPad 4).

I have an in-app shopping app. The function "Restore purchases" is implemented.

I exit iTunes (in the settings) and update the application. Then I click “Restore purchases” and enter the email address and password for any valid account in the form of a sandbox with many (> 10) purchases made earlier. But, restoring the process, I kill the application. Then I go to settings and log out again.

Now this is an adventure time! When I run the application again, it asks me for a password for a previously registered user. Alright, alright, I get into it, and everything is fine. Then I can close and restart the application again, everything will be fine.

But after that, I log out again and restart the application ... and I see the iTunes password hint (for a previously registered user, again). While debugging my application in Xcode, I test the array [[SKPaymentQueue defaultQueue] transactions]... and it's empty! In addition, the delegate SKPaymentQueuedoes not receive a signal paymentQueue:updatedTransactions:.

How is this possible? So far, I can’t even clear anything - after reinstalling the application iTunes again asks for a password.