hi, I have an unlocked HTC One X international version. When I inserted a new T-Mobile micro SIM card the phone part worked fine and I could make and recieve calls. Data did not work and when I navigated to the APN setting it flashed a message that SIM card is missing and please insert SIM. I went to the T-Mobile store and the agent who was very helpful was on the phone with level 2 support. They asked us to try a new SIM Card and that gave exactly the same result. They gave up. The agent later said that the new micro SIM cards were HTC One S compatible and I should try an older SIM card. He made a few calls and found one store that had an older Micro SIM (Plain white front without people's pictures printed on the card). I got that SIM and One X recognised the APN settings and everything worked fine including Edge data. I was wondering if anybody elso experienced this and am concerned that if I need a SIM card in the future then T-Mobile's new SIMs will remain incompatible.