Hi, Trying to pass on my Skyrocket to a friend. I had it unlocked with a code provided by AT&T. When the T-Mobile Sim from their phone was inserted, everything looked good. Signal, messaging, calls all good. When trying to get on the internet, no go. The Skyrocket has the latest software and it is not rooted. The current Sim is for a basic Galaxy S. Does it need an updated Sim?