Here is what worked for me.
1) go into Settings
2) select Mail, contacts, Calendars
3) check if you have an iCloud account and tap on it.
4) scroll that window up in order to show the "Delete Account" red bar.
5) select the "Delete Account" red bar.
6) it will ask if you want to keep your contacts, calendar, Safari favorites, etc. on your device.
7) say yes and keep all the data in your device.
8) hit the home button
9) double click the home button and delete all apps in the recent file bar at the bottom of the screen (touch and hold one app from the bottom of the screen until all of them wiggles, then delete each one by selecting the small red circle on the upper left of each one Just the ones on the bottom recent files bar)
10) select the home button again.
11) hold down the power button until the slide to power off shows on the screen.
12) slide the arrow button to the right to power your device off.
13) power your device on again by holding the power button until you see the apple logo on the middle of the screen. (this boot up sequence could take few minutes.
14) once the device is on go to settings and add the iCloud account again. (Select Mail, Contacts, Calendar. on the Accounts section select add Account... Select iCloud and enter your Apple ID and password for this device.
15) then turn no the options you want to be synch (contacts, calendar, reminders, safari, photo stream, etc.)
16) select the home button.
17) open the AppStore and select the update page. It should work normal, so update the apps you need to.
18) Done, now it should work fine.