I had serious problems with unlocking an AT&T phone(Nokia) several years ago;the codes just wouldn't work. I just kept going in to the AT&T store(they existed then) at 8:30 AM and causing problems until one of the employees somehow found an unlocked model of the same phone to exchange for mine.

End of August this year I got a Motorola Razr unlocked for $25.00 in SF, since I just didn't want to go through the code hassle or looking for the unlock booth at the Braderie Lille. My French sim card works just fine. Reading French isn't the problem. The codes just don't always work.