this is the responsible function inc/classes/BxDolVotingQuery.php
function getTopVotedItem ($iDays, $sJoinTable = '', $sJoinField = '', $sWhere = '')
{
$sPre = $this->_aSystem['row_prefix'];
$sTable = $this->_aSystem['table_track'];
$sJoin = $sJoinTable && $sJoinField ? " INNER JOIN $sJoinTable ON ({$sJoinTable}.{$sJoinField} = $sTable.`{$sPre}id`) " : '';
return $this->getOne ("SELECT $sTable.`{$sPre}id`, COUNT($sTable.`{$sPre}id`) AS `voting_count` FROM {$sTable} $sJoin WHERE TO_DAYS(NOW()) - TO_DAYS($sTable.`{$sPre}date`) <= $iDays $sWhere GROUP BY $sTable.`{$sPre}id` HAVING `voting_count` > 2 ORDER BY `voting_count` DESC LIMIT 1");
}
as you can see it here voting_count > 2 maybe it needs to have vote of 3 or more in order to display something