samsung galaxy s i9000 update and messaging problems

Jan 1, 2013
my current miui version is 1.11.4.......and i see on this website are already 2.12.28/ that normal??? i already click 'check for update' button but it said i got the latest version. on messaging part i tried to message people with my other sims but it wont work i wonder whats wrong with that......can someone please help me on how to solve this (btw im still new to this os)