Well as long you follow the install instructions properly you should be good. If you wii firmware is on 4.2, then you will not be able to play PAL on your NTSC. Well kinda confused there. When you say NTSC box do you mean the wii or the TV? If you mean the tv, then its just a matter of if your TV can display PAL or not I think.... Not really sure cause my tv is PAL capable. My wiikey2 doesn't have a problem with loading either region games.