Guys, if I remember reading correctly. David has an W580i locked to AT&T just like I do. I believe the guide works... my phone thinks its unlocked, after using Simox's guide, but still will not recognize a T-Mobile sim card. I appreciate the hard work he did on the program & guide, but have tried the method with a few different firmwares, and no dice. All padlocks open, and phone works fine, other than that it's still locked to AT&T.