[cfong]

You are right, officially Sprint doesn't support text message in China, Korea, or Japan. I even called Sprint's international support, they couldn't make it work. I don't think it has anything to do with how I used it. The text message I received from Sprint (ironic isn't it) when I first turned on my phone gave me instructions on what to enter to call a US phone number. Sending text message I should enter the same number, but it never worked. Since I could receive text messages from Sprint, I suspect that preventing me from sending text is Sprint's way of forcing me to pay the high int'l roaming rate ($2.29 per minute in China, $2 per min in Japan).

My answer to that was to get a local SIM.