previously activated AT&T iphone! IAsign on PC worked!
I am able to successfully activate my old Cingular SIM card using the windows PC.
If you need help let me know. I am writing a step by step procedure for my own records including picture of my command windows. I don't really want to duplicate the great efforts of other who are working more harder than me to finally unlock the iphone. but if you need it or you have any question Let me know:
the thing about my iphone is as follows:
a)I bought the iphone from apple
b)I activated the iphone through itune and att. call it offical activation if you wish!
c) I used jailbreaker to customize my ringtones
c) I called att a week later and canceled my att contract. (before the 14 days grace period)
d) my phone ipod, wifi was working after the cancelation of the contract.
e) I gather all the necessary files to activate my SIM (including the plist files which i generated at https://ookoo.org/iphone/iasign.php). I just hooked up the iphone to my PC. Stopped itune and then executed the iphoneinterface and activated my SIM. I did not need to deactivate. I just replaced the /System/Library/Lockdown/iPhoneActivation.pem in my iphone with the new one in the instruction for both mac/and windows and then executed th executable generated by https://ookoo.org/iphone/iasign.php with my plist file.