Cannot enable automatic downloads on iPad

I can't enable Automatic downloads on my iPad 2 iOS 4.3.3. I go to Setting > Store, and turn on Automatic Downloads for Music, Apps and Books. The buttons switch to ON for 6 seconds and then they turn themselves off. Try restarting and syncing with Mac, but still not working. How to resolve the issue?On your iPad, just sign out of your iTunes account and then sign back in again. That will be