According to guys at MoDaCo uncovered something disappointing that AT&T variant of the HTC One X is Locked. Paul O’Brien tried to unlock device via HTCDev but got wasn’t able to do this. He added that other AT&T retail units have showed the same result which is a “MID ERROR 160″ message. So, now we know that this version of HTC One X is different from International version of device. There’s a wide range of reasons why a carrier would want to go through the trouble of requesting a device’s bootloader remain locked and it’s also very possible that a future update could fix this roadblock.