Written on: 16/08/2012
My phone when I bought was manufacture unlocked. However, after I manually upgraded firmware from ICS 4.0.3 TO ICS 4.0.4 it asked for 'Network Unlock Control Key'. I found cellunlocker.net and gone through its website to get the key. I got the unlock keys very quickly after payment (2 hours after). I applied the unlock key first and it did not work. Then I applied the Defreeze key then 'unlock key' next as per troubleshooting and it worked. Many thanks!