Ever since I upgraded my IPAD 2 to I0S5 I can't download books to my kindle/amazon app. What do i need to do to get the books to download and open? I have tried deleting the kindle icon and reinstalling it. I tried deleting all the books and redownloading. Whenever I try to open, it gives me an error message and to reinstall. Is it because I need an Icloud acccount?