Errori nel select tra più tabelle

[zampi91]

 $this->Password = md5($this->Password);    
        $Query = "SELECT a.Ban, a.Activation, i.Hash FROM Sd_Auth a, Sd_Info i WHERE i.ID = a.ID
                    AND a.NickName = '".$this->NickName."'
                    AND a.Password = '".$this->Password."'";    
        $Result = mysql_fetch_array($Query);