I have an iPhone 4 with a 01.59.00 baseband running iOS 4.0.1 (i dont upgrade often) with ultrasn0w 1.2.5 and I keep getting "SIM Invalid" or something similar as an error. I recently switched to a new T-Mobile SIM card from an older T-Mobile SIM under the same iOS and managed to unlock and use the previous SIM so I am unsure of the problem. I have restarted and uninstalled/reinstalled ultrasnow dozens of times and I have reset network settings so all of that is blank, but nothing seems to work. The SIM card I am using now came as a microSIM (so no cutting issues) and the account is activated already. Any ideas?