I was having the same problem as Ghostface but then I did something and it worked.
1.) Create the pokemon you want.
2.) Save it to a folder (desktop preferably)
3.) Open it with a word editor.
If you didn't know this in order for the cheat to work, the cheat must have the same "gameid" as your game. I removed all the cheats from my ARDS and got the gameid of my Heart Gold and changed the gameid in the file to the one in my game. Then I moved the cheat to my ARDS and it worked.
IPKE 4DFFBF91 for US Heart Gold
