Just a heads up that I called AT&T today and asked for my unlock code and they provided it. Unfortunately I left my phone at home today, so I will have to try it when I get home. I don't know if it makes a difference, but my company has a discount with AT&T thus when I call in I am routed to the "enterprise support" area. I gave the person my IMEI number and they cam back with two unlock codes, which is different that any other times I have asked them for an unlock code. They did tell me to try one of the numbers first, and try the second one if the first one fails. I'll power off my phone tonight, put in my T-Mobile SIM card from my work Blackberry, and hopefully it will ask for the unlock code so I can try them out. I'll report back my results later today.