After the release of Super Smash Bros. Brawl, some gamers complained of disc errors and general game problems. Nintendo concluded that the issue was with the dual-layering of the SSBB DVD. Since then there's been some murmurs online regarding the upcoming Mario Kart Wii.
Japanese gamers have been reporting problems with Mari Kart that were similar to the Brawl issue, but Nintendo says that there's no need to worry. They claim that they've received no complaints regarding the performance of the game. It can't be the same exact issue as Brawl because Mario Kart isn't dual-layered, so we'll see when the game hits stores.
