With new iMacs comes new software. Apple has released a Boot Camp update for Thunderbolt iMacs.



From TUAW:

The small update (the download is just 638 KB) can be found via Software Update or Apple's website and offers a specific fix. According to Apple, the update "...addresses issues with Japanese and Korean keyboards on early 2011 iMac."

  Boot Camp update for Thunderbolt iMacs available