I have an iPhone 4 ios 5.1 baseband 4.12.01 When i was using it, it was working perfectly with SAMprefs. I dont remember how i set it up the first time so I cant tell you how it was done. I bought myself a new phone and i'm giving this one to my little brother and i understand that you need to re-do the whole sampref process in order to unlock this new simcard with the phone. So heres what i did and i still can't get the phone to connect to t-mobile. 1) went into utilities, tapped de-activate phone & De-Activate iPhone (Clear push) 2) Enabled SAM and chose method as: BY COUNTRY AND CARRIER. Selected country as UNITED STATES selected carrier as AT&T and simID is 310170 (1 of 2 that only works out of 7) 3) Tapped more information and coppied IMSI number under SAM DETAILS 4) Tapped SPOOF REAL SIM TO SAM then OK after SPOOFED screen. 5) went back to main screen and method is on MANUAL and pasted the copied IMSI Number in the IMSI box (removing what was in it before) 6) Plug it into iTunes and the phone pops up with MATCHING ICCID numbers. 7) Unplug iPhone, close iTunes 8) i go back into SAMprefs and disable it and close the app 9) re-connect to iTunes i get message that says SIM CARD INSERTED IN THIS IPHONE DOES NOT APPEAR TO BE SUPPORTED message. (this is expected) 10) i close iTunes and re-open it and shoes me the SIM CARD INSERTED IN THIS IPHONE DOES NOT APPEAR TO BE SUPPORTED message. i unplugged waited for a little bit to see if it'll connect to tmobile, but it doesn't... Can someone please review this with me and help me figure out why the hell this isn't working? THank you. Hopefully this post can help people who are having same problem.