Howdy,
I'm having problems with my parents nintendo Wii and the reaction speed. I have my own nintendo and I have no problems like this what so ever.
Basically using wii sports tennis as the example, you need to swing a good 1/2 second before the ball gets near you in order for your mii to react in time to actually hit the ball. On my nintendo you play as you would a normal game of tennis you swing once the ball is at you and it works perfectly.
The same problem happens in every game, we thought it was the sensitivty on the remotes which we changed and it makes absolutely no difference.
On mine as you swing the remote your mii swings at the same time, on my parents it is delayed around 1/2-1 second.

Does anyone have any suggestions on how I can fix this? Any ideas would be appreciated.

Thanks

why not give nintendo a call....they're very helpful and you can actually understand them