I have a iphone 3gs 32gig. It is in 3.1.2 and unlocked with blackra1n. I put my t-mobile sim card and friend's sim card and it dose work. but the signal is very weak, it only work outside and only have 1-2 bars of signal... Not working at home, no signal no service... Anyone know how to fix this problem? i have tried to reset the network setting and still the samething.