When programming in a Nissan prox twist key it is possible that the TCode PRO will give a message that the key has programmed successfully but the key isn't programmed at all.  It seems that this isn't a key issue because OE and ClearCom keys have been known to have the same issue. The fix appears to be that the TCode needs to go through the key programming process up to 10 times before it will finally program the key correctly.  So, if the TCode screen says, “Programming successful, do you want to program more keys?  Yes?  No?” but the key is still not programmed, select "Yes." again on the TCode to try and program the key again.  If that doesn’t work, select “Yes” again and try to program the key again.  If that doesn’t work, do it again.  Over and over up to 10 times before it may program in.