[iPhone 3G]Unlock on 3.1 FW not working on Windows using Ultrasnow
I bought a friends iPhone 3G. Downloaded a custom IPSW for 3.1FW. Did shift restore worked fine. Now, I tried to run the ultrasn0w. That also went fine.
Now, I have a fully jailbroken iPhone 3G with FW 3.1 but it is not getting the signal from the sim card.
What possibly is wrong here ?
Is it possible that the phone when at 3.0 FW was not unlocked using Yellowsn0w or Redsn0w, as I am not aware of the history.
Thanks, any help much appreciated.