My iPad 2 has stopped running properly on our wi-fi this afternoon. When I try to access a website in Safari, the Loading Progress bar at the top of the screen starts to turn blue at its left-hand side as expected but stops after it has gone about 1/10 of its travel. Then I get a pop-up saying "Cannot Open Page: Safari cannot open the page because it is not connected to the internet".
However the wireless indicator (the three circle segments icon) is showing and under Settings the wi-fi network name has a tick symbol next to it.
If I 'forget' the network and re-join and re-enter the router password, the wi-fi is OK again but if I put the iPad down for a while, when I pick it up again, I'm back with the situation in my opening paragraph.
The wi-fi is running fine - I'm using it now to send this post from my lap-top. Possibly some setting or other has been changed but I have no idea what it is and would welcome any advice.