After a long long story, I got the unlock codes for my Galaxy. They sent me the NCK code (that the system prompts with a SIM from another carrier). I have inserted the NCK code and my phone looks unlocked. But sometimes it continuously show the roaming icon in the status bar. They also sent me a MCK code. Where and for what is this code? Does anyone know? Is the MCK not informed that's causing the "roaming"? Thanks!