My wife's S3 was just upgraded to the newest OS version 4.3. Ever since, it will not stay connected to WiFi, the mobile data is spotty, and the overall signal is worse than it ever was. My question: How to downgrade to the previous version that was working perfectly before Samsung started pushing notifications to upgrade every day and we finally gave in? I am not interested in rooting as there is too much time left on the contract to be messing with that. Any suggestions? Oh, and it is the Sprint version in the US.