Default Help:After export & emport contacts show "??????"

one guy called me know.he is very good person

he say after import and export the contacts to other phone file name is CSV i think...but he say while he put the contacts into the phone names showed up question mark like "???????"

i suggested him to use other phone he say was same.i think he got the contacts from iphone.but many times i got from iphone and i put it in android device had no problem
ROM: CyanogenMod 11 snapshot