I've had my iPad for a year now and have never encountered problems until now. It runs something like this; I buy an App from the App store, log in with the correct password. An icon appears on my desktop, Thedownload begins and within 10 seconds or so, simply vanishes. When I return to the App Store, it is still there as if I hadn't bought it at all. I've tried 'cold' shutdowns (many times) and still no joy. Does anyone have a suggestion?