No Internet Connection after Waking Up my iPad 2

Whenever the iPad has been sleeping for a long time (during the night for example), the next morning when I turn it on, it says it's connected to the WiFi network, and it certainly is because I can see it in the WiFi settings, But whenever I want to use the Internet I can't. I have to shut down WiFi and turn it on again and then it works .My router is working perfectly and the iPad is connected to it with an appropriate Internal IP (192.168.1.38).
I tried already resetting my router to its factory settings. And tried holding down the Power and Home buttons together for about 10 seconds, ignoring the red power-off slider, until I see the Apple logo, but it doesn't seem to work. I would like some help, this problem persists. If anyone could at least tell me if this is a common occurrence and if Apple is looking into it or not, I'd be happy.
Thanks!
