Umleitungsfehler

public function Login(){
            if(isset($_POST['username']) AND isset($_POST['password'])){
                $a = $this->FilterText($_POST['username']);
                $b = $this->FilterText($_POST['password']);
                if( empty($a) || empty($b) ){ $error = "Por favor, introduce tu usuario y contraseña para conectarte"; }
                elseif( $this->CheckLogged($a, $this->Hash($a, $b)) ){ header("LOCATION: ". PATH ."/me"); exit; }
                else{ $error = "La contraseña no coincide con el usuario."; }
                if( !empty($error) ){
                    $_SESSION['LOGIN_ERROR']     = $error;
                    $_SESSION['LOGIN_USERNAME']  = $a;
                    $_SESSION['LOGIN_PASSWORD']  = $b;
                }
                header("LOCATION: ". PATH ."/index.php?username=". $a ."&rememberme=false&focus=login-username");
                exit;
            }
            header("LOCATION: ". PATH ."/index.php");
            exit;
        }

public function Login()
{
    if (isset($_POST['username']) && isset($_POST['password'])) {
        $a = $this->FilterText($_POST['username']);
        $b = $this->FilterText($_POST['password']);


        if (empty($a) || empty($b)) {
            $error = "Por favor, introduce tu usuario y contraseña para conectarte";
        } elseif ($this->CheckLogged($a, $this->Hash($a, $b))) {
            $_SESSION['LOGIN_USERNAME'] = $a;
            $_SESSION['LOGIN_PASSWORD'] = $b;


            header("LOCATION: ". PATH ."/me"); exit;
        } else {
            $error = "La contraseña no coincide con el usuario.";
        }


        if(! empty($error)) {
            $_SESSION['LOGIN_ERROR'] = $error;
            $_SESSION['LOGIN_USERNAME'] = $a;
            $_SESSION['LOGIN_PASSWORD'] = $b;
        }


        header("LOCATION: ". PATH ."/index.php?username=". $a ."&rememberme=false&focus=login-username"); exit;
    }


    header("LOCATION: ". PATH ."/index.php"); exit;
}