i'm trying to update from 4.3.5 to current. problems from the get-go. first, no "update" button in my Setting section. so i try to do it from iTunes, but i'm warned to back up first. i do the backup, yet several new apps aren't backing up. someone from another forum suggested- " If it still won't back up, you may have an app that is preventing the backup from succeeding. To locate which one, go to Settings>iCloud>Storage & Backup>Manage Storage, tap the name of your device under Backups, under Backup Options tap Show All Apps, then turn them all to Off (including camera roll) and try backing up again." this doesn't work either because there is no iCloud tab in my settings section. i'm stuck.