This is the weirdest thing that happened to me. I got the official Tmobile unlocked code when I got my Vibrant 2 months ago. I have both ATT and Tmobile service. Very easy. There's two way to unlock it per Tmobile's instructions. Please be advised there are two different ways to unlock this device. It is very important that the instructions are followed as listed. If using a T-mobile SIM card: 1. Put in a T-Mobile SIM card. 2. Turn on the handset. 3. Enter: #7465625*638*Unlock Code# If using a Non T-Mobile SIM card: 1. Put in the Non T-Mobile SIM card. 2. Turn on the handset. 3. Enter the Unlock Code provided by T-Mobile. Note: DO Not enter #7465625*638*unlock code# with a non T-Mobile SIM card, as this causes the handset to freeze. If you receive an error message while performing the instructions do not make any further attempts to unlock the handset. Please be aware that if an excessive amount of incorrect attempts are made, the phone will be permanently locked. You will need to verify the IMEI by pressing *#06# and contact Customer Care for support. Anyways, I just popped in my ATT sim into the Vibrant and used the unlock code I was given. No problem for almost two months. I switch Tmobile/ATT sims with the Vibrant. So this past weekend, when I put the ATT sim back into the Vibrant, the phone asked for the unlocked code again. It's a good think I save all of my emails with the unlocked code. But is this normal to have an official unlock code and the phone "relocks" itself? This is the first time I've ever had a GSM phone (with either ATT or Tmobile "relock" itself").