The whatsapp push notification work fine under 2g, but in 3g, sometimes it shows error with your device push notification and it arrives really late, or never, twitter push notification is working well. All others are not at all functioning, which used to function properly before, like LINE, Hike, Skype. In the case of skype, the app is not running in the background, and so we canot receive any calls when the app is closed.... what the hell is happening???????