My dad's iPhone 3GS is stuck on iOS 4.2.1 and I cannot upgrade it to 4.3.3 I tried downloading the update from iTunes without any luck. Updated all the software on his MBP to ensure he had the latest version of iTunes. I then tried to update the iOS software with no luck. What is the next step? I want him to be up to date so he can benefit from wireless synching when iOS 5 is out.