Patch Pal To NTSC affects Gameshark codes?

[Adenosine]

Greetings.

Does "patching" a game (Victorious Boxers) from the PAL version to NTSC affect the gameshark code?

I just obtained a copy of this game and I've tried all the gameshark/codebreaker codes available but they still won't work. I think the copy has been patched from pal to ntsc because the opening video of the game is not centered on the screen. I think that's a sign that the movie was a pal one. The actual game doesn't have the same off centered problem as with the opening video. I think it's the effect of a pal to ntsc patching.

I've tried both PAL and NTSC codes and none work. I hope someone can help me with this. Thanks in advance people.