hello to whom ever is reading this..

i downgrading my phone to 1.0.2, and use the unlocking and activation video tutorial (part 1 and 2). i followed all the steps the same thing the person in the video was doing i was doing fine..after everything i thought my phone was unlocked but i inserted a tmobile sim and it tells me
**Incorrect Sim** this iphone must be used with an approved SIM.

now what??? im stuck dont know what to do..if anyone can help that would be great!..my email is [email protected]

thanks in advance