I recently got round to updating my iPhone 4s to IOS8.2 at long last. Ever since I rant he update I keep getting little pop ups asking me to enter my iCloud login password. It seems to happen when I click on messages to view my texts. It doesn't happen every time but it does it 3 or 4 times a day regardless of whether I enter the password or not. Any ideas how to stop this annoying little bug?