problem with multiple apps in ios 7

I have a very big problem with push notifications. I think it might be a bug. when I open some apps I get a message that says to connect to iTunes to get push notifications. but guess what. I connected to iTunes and nothing happened.. I still don't receive these notifications. I tried deleting and reinstalling these apps but the problem still persists. the apps are viber, what's app, hattrick. strangely there are some apps where I don't receive this message. if any of you has a solution I would appreciate very much. if not I think I will downgrade.. thanks.