I just added the Korean keyboard to my 3rd gen iPod touch and I had no problems writing in Korean, but when I tried to text myself from Google Voice to TextPlus, it wouldn’t send the msg with Korean in it. Try powering off your iPhone and turning it back on, and if that doesn’t work, I would try restoring it. If that still doesn’t fix it, call Apple (or take it in to an Apple Store). They have great customer service.