i have bought a gevey sim,and its dont work for my iphone 4 on 4.3.2.i have do all the steps and about 20 tries and he give no service,my iphone is locked for at&t.
but i dont live in USA.
try to remove your sim, turn off your phone , plug in your sim+gevey and then turn on phone, wait until 1 bar shows up, dial the number, and IMMEDIATELY go to airplane mode. within 5 secs. and then wait for the sim failure and it should be working!