Mayura ∙ 28 Jan, 12
Recently many AdSense accounts has been disabled with the mention of Invalid Click Activity or Policy Violations eventhough the AdSense user has no responsible over it. But Google doesn't care them.
If it's claimed due to Invalid Click Activity, you may appeal from here ~ http://www.google.com/support/adsense/bin/request.py?contact=invalid_clicks_appeal
Further you can check AdSense Help Forum for related discussions.