unlocked AT&T iPhone? I read somewhere that you can't access the Cellular Data Network on an AT&T Factory Unlocked iPhone with an AT&T SIM due to Apple, AT&T, and/or IOS 6, but performing the SIM swap trick with a T-Mobile SIM will work so you can change the APN settings for Data/MMS. If I order a T-Mobile Compatible Straight Talk SIM, will the iPhone recognize it as a T-Mobile SIM, or would I need to use an actual T-Mobile SIM?