You got a same problem with me. Please see http://www.supriyadisw.net/2008/01/my-google-adsense-account-disabled-mysteriously

I don’t know what happen with me too

Thanks

Hello Rajendra Ale Magar,

While going through our records recently, we found that your AdSense
account has posed a significant risk to our AdWords advertisers. Since
keeping your account in our publisher network may financially damage
our advertisers in the future, we’ve decided to disable your account.

Please understand that we consider this a necessary step to protect the
interests of both our advertisers and our other AdSense publishers. We
realize the inconvenience this may cause you, and we thank you in
advance for your understanding and cooperation.

If you have any questions about your account or the actions we’ve
taken, please do not reply to this email. You can find more information
by visiting