I too had the same problem with my iPad 3. It lasted about a week and I tried everything under the sun to resolve it, nothing worked. I even called Apple (and they wanted to charge me $20 to answer my question) and they didn't even know how to fix it. It eventually just fixed itself. I have no idea what caused it and have no idea how it fixed itself. But I do hope it never happens again, cuz there's nothing worse than having to go thru every single app in your purchased list to see which apps need updating