I believe that I was successful in jailbreaking and unlocking my iPhone4 that I used with AT&T in the US with Greenpoison. (If it is any proof, I have the ultrasnow check marked within the Cydia/Loader...this does mean it is unlocked/jailbroken, right?) I am currently in Japan and I entered into a voice and data contract with Docomo (a carrier that is not an official carrier of the iPhone). However, when I entered the sim, it either shows only 1 bar, No Service, or Invalid Sim. 1. I was told that in the Settings-General-Network, there should be a Cellular Network (or something similar) where I can change the APN. I do not seem to have this. 2. I tried going to http://www.unlockit.co.nz/, but Docomo in Japan was not one of the choices. 3. Occasionally, within Settings, Carrier appears, but it is set on Automatic and says that it cannot show the network list. What is wrong? What can I do?