I have a friends phone:

I don't know the steps he used, but basically he had a 1.1.1 iPhone, did a jailbreak, unlocked it to use with T-Mobile SIM card, then updated to 1.1.2.

I have successfully brought the functionality back to phone by downgrading to Version 1.0.2(1C28), but still have Modem Firmware 04.02.13_G (1.1.2). the IMEI begins with-0049, WiFi is un-touchable, not able to be launched, wether ya try to touch it in Settings, or Settings>General>Network - says Wi-Fi No Wi-Fi, and I am getting the message: Incorrect SIM - This iPhone must be used with an approved SIM.

Any assistance to get WiFi back so i can install SSH to unlock again, or downgrading the Modem Firmware to true Version 1.0.2/1.1.1 so i can jailbreak and unlock successfully again would be more than appreciated.

Any assistance or guidance towards the right direction for that matter would be much appreciated as well!!

Thank you for your time, if any further information is needed to diagnose/determine a remedy for this problem, don't hesitate to ask!!

better instructions in this thread:

http://www.hackint0sh.org/forum/showthread.php?t=21738