chiizu
PPPPPPPPPPPPPPPPP RNG
Make sure you are entering times as 24-hour times.hmmm, double checked my mac address tried multiple dates & times, still nothing.
Make sure you are entering the game from the DS menu and not soft-resetting.
Make sure you are not holding any buttons between the time you select the game from the DS menu and the time that the initial logo appears.
Make sure you actually have the correct IVs (catch a high-level poke and check with Metal Kid's calculator)
Make sure you are using an original DS or a DS Lite.
Make sure you are using a retail game cart and not a flash cart (parameter ranges will be different in this case).