Instead of hacktivating, you can just unlock your iPhone by IMEI and activate it with any SIM card you want. It will be permanently unlocked. http://unlock.senseiphone.com/
http://senseiphone.com/hacktivate-iphone-ios5-activate-without-simcard-04193117/
Fix:
Only Compatible SIM card from a supported carrier may be used to activate iPhone.
Please insert the SIM card that came withyour iPhone or visit a supported carrier's
store to receive a replacement SIM card.
Hacktivate iPhone
Hacktivate iOS 5
Bypass iPhone Activation
Bypass iOS 5 Activation
Activate iPhone without SIM Card
Activate iOS 5 without SIM Card