If you believe a user was marked as a cheater incorrectly, you can re-instate that user and whitelist his IP address.
Please go to the winners tab.
Then enter the email address of the user that was disqualified in the section marked "look up by email"
On this page you can re-instate the user by clicking the re-instate user button.
Please note that the user will be whitelisted, so even if he cheats again, he will not automatically be marked as a cheater. Use this option only if you truly believe this user has not cheated.