Save files saved in the '.sav' or '.SAV' format are the same. Transferring them to your M3i, as long as you are using Sakura, should (not usually though) work. If they don't, then Sakura will give an error. Simply press L+R+A+B as instructed, and the game will boot up, no problems, with your save file. And if it don't, well then your save is a BAD save.