Dear lllaass
My first message is a response to Apple's online article (Article: TS3305) entitled 'iPad and iPod touch: Unable to use YouTube or Push notifications' (URL: http://support.apple.com/kb/TS3305?viewlocale=en_US&locale=en_US), which is also mentioned at the top of this page.
In this article, may I draw your attention to the 'Resolution' section, which is somewhat vague, especially the word 'verify' used in steps 2 and 4.
I have searched for and tried various methods suggested in the Apple Support Community Forums but none works.
I hope the information mentioned in this message helps you in giving a possible solution to me and other members in the Forums. Sorry for the lack of clarity in the first message.
Many thanks in anticipation of your reply.