Mario Kart Wii Disc Read Problems?

Return of the Wii disc-read errors? Maybe! This echoes when Super Smash Bros. Brawl launched in Japan, there were reports of disc-read errors were blamed on the console’s optical lens being “soiled” by dust and cigarette smoke, making it unable to read the dual-layer disc. This time around, some Japanese gamers are also reporting read errors, freezing and crashing — however, Mario Kart Wii is a single layer disc, and thus, the Wii shouldn’t have optical lens issues. Nintendo has said its not aware of the problem, and the issue doesn’t seem to be rampant, so.
Dirty Lens with Mario Kart Wii [ゲーム屋さんのお店だより via Go Nintendo via Dtoid]