You already bought the S2? Put your sim card in it and fire it up? It should work if it's already unlocked and you have a T-Mobile SIM card. How/why would T-Mobile ban S2's and only S2's? I know more T-Mobile users who have 3rd party unlocked phones (i.e. IPhone) than phones that were bought from T-Mobile. It doesn't make sense for them to target one phone.