Não está salvando aros, acos e/ou aros_acos

AppController.php

<?php
App::uses('Controller', 'Controller');

class AppController extends Controller {
	
	public $helpers = array('Session', 'Html', 'Form');

	public $components = array(
		'Session',
		'Acl',
		'Auth' => array(
			'authenticate' => array(
				'Form' => array(
					'fields' => array('username' => 'usuario', 'password' => 'senha'),
					'userModel' => 'Usuario'
				)
			),
			'loginAction' => array('controller' => 'usuarios', 'action' => 'login'),
			'logoutAction' => array('controller' => 'usuarios', 'action' => 'logout'),
			'authError' => 'Você não tem permissão para acessar esta página.',
			'authorize' => array(
				'Actions' => array('actionPath' => 'controllers')
			)
		)
	);

	public function beforeFilter() {
		$this->Auth->allow('*');		
	}


}

Grupo.php

<?php
App::uses('AppModel', 'Model');

/**
 * Grupo Model
 *
 * @property Usuario $Usuario
 */
class Grupo extends AppModel {

	public $useTable = 'grupos';
	public $displayField = 'nome';
	public $actAs = array(
		'Acl' => array('type' => 'requester')
	);	

/**
 * Validation rules
 *
 * @var array
 */
	public $validate = array(
		'nome' => array(
			'notempty' => array(
				'rule' => array('notempty'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
		'ativo' => array(
			'boolean' => array(
				'rule' => array('boolean'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
	);

	//The Associations below have been created with all possible keys, those that are not needed can be removed

/**
 * hasMany associations
 *
 * @var array
 */
	public $hasMany = array(
		'Usuario' => array(
			'className' => 'Usuario',
			'foreignKey' => 'grupo_id',
			'dependent' => false,
			'conditions' => '',
			'fields' => '',
			'order' => '',
			'limit' => '',
			'offset' => '',
			'exclusive' => '',
			'finderQuery' => '',
			'counterQuery' => ''
		)
	);


	public function parentNode() {
		return null;
	}

}

GruposController.php

<?php
App::uses('AppController', 'Controller');
/**
 * Grupos Controller
 *
 * @property Grupo $Grupo
 */
class GruposController extends AppController {

	public $uses = array('Grupo');

/**
 * index method
 *
 * @return void
 */
	public function index() {
		$this->Grupo->recursive = 0;
		$this->set('grupos', $this->paginate());
	}

/**
 * view method
 *
 * @param string $id
 * @return void
 */
	public function view($id = null) {
		$this->Grupo->id = $id;
		if (!$this->Grupo->exists()) {
			throw new NotFoundException(__('Invalid grupo'));
		}
		$this->set('grupo', $this->Grupo->read(null, $id));
	}

/**
 * add method
 *
 * @return void
 */
	public function add() {
		if ($this->request->is('post')) {
			$this->Grupo->create();
			if ($this->Grupo->save($this->request->data)) {
				$this->Session->setFlash(__('The grupo has been saved'));
				$this->redirect(array('action' => 'index'));
			} else {
				$this->Session->setFlash(__('The grupo could not be saved. Please, try again.'));
			}
		}
	}

/**
 * edit method
 *
 * @param string $id
 * @return void
 */
	public function edit($id = null) {
		$this->Grupo->id = $id;
		if (!$this->Grupo->exists()) {
			throw new NotFoundException(__('Invalid grupo'));
		}
		if ($this->request->is('post') || $this->request->is('put')) {
			if ($this->Grupo->save($this->request->data)) {
				$this->Session->setFlash(__('The grupo has been saved'));
				$this->redirect(array('action' => 'index'));
			} else {
				$this->Session->setFlash(__('The grupo could not be saved. Please, try again.'));
			}
		} else {
			$this->request->data = $this->Grupo->read(null, $id);
		}
	}

/**
 * delete method
 *
 * @param string $id
 * @return void
 */
	public function delete($id = null) {
		if (!$this->request->is('post')) {
			throw new MethodNotAllowedException();
		}
		$this->Grupo->id = $id;
		if (!$this->Grupo->exists()) {
			throw new NotFoundException(__('Invalid grupo'));
		}
		if ($this->Grupo->delete()) {
			$this->Session->setFlash(__('Grupo deleted'));
			$this->redirect(array('action' => 'index'));
		}
		$this->Session->setFlash(__('Grupo was not deleted'));
		$this->redirect(array('action' => 'index'));
	}
}

Usuario.php

<?php
App::uses('AppModel', 'Model');
App::uses('AuthComponent', 'Controller/Component');

/**
 * Usuario Model
 *
 * @property Grupo $Grupo
 */
class Usuario extends AppModel {

	public $useTable = 'usuarios';
	public $displayField = 'nome';
	public $actAs = array(
		'Acl' => array('type' => 'requester')
	);

/**
 * Validation rules
 *
 * @var array
 */
	public $validate = array(
		'grupo_id' => array(
			'numeric' => array(
				'rule' => array('numeric'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
		'ativo' => array(
			'boolean' => array(
				'rule' => array('boolean'),
				//'message' => 'Your custom message here',
				//'allowEmpty' => false,
				//'required' => false,
				//'last' => false, // Stop validation after this rule
				//'on' => 'create', // Limit validation to 'create' or 'update' operations
			),
		),
	);

	//The Associations below have been created with all possible keys, those that are not needed can be removed

/**
 * belongsTo associations
 *
 * @var array
 */
	public $belongsTo = array(
		'Grupo' => array(
			'className' => 'Grupo',
			'foreignKey' => 'grupo_id',
			'conditions' => '',
			'fields' => '',
			'order' => ''
		)
	);



	public function beforeSave() {
		if(!empty($this->data['Usuario']['senha'])) {
			$senha = $this->data['Usuario']['senha'];
			$senha = AuthComponent::password($senha);

			$this->data['Usuario']['senha'] = $senha;
		}

		return parent::beforeSave();
	}

	public function parentNode() {
		if(!$this->id && empty($this->data))	 {
			return null;
		}

		if(isset($this->data['Usuario']['grupo_id'])) {
			$grupoID = $this->data['Usuario']['grupo_id'];
		} else {
			$grupoID = $this->field('grupo_id');
		}

		if(!$grupoID) {
			return null;
		} else {
			return array('Grupo' => array('id' => $grupoID));
		}
	}

	public function bindNode($usuario) {
		return array(
			'model' => 'Grupo',
			'foreign_key' => $usuario['Usuario']['grupo_id']
		);
	}

}

UsuariosController.php

<?php
App::uses('AppController', 'Controller');

/**
 * Usuarios Controller
 *
 * @property Usuario $Usuario
 */
class UsuariosController extends AppController {

	public $uses = array('Usuario');

	public function login() {
		if($this->request->is('post')) {
			if($this->Auth->login()) {
				$this->redirect($this->Auth->redirect());
			} else {
				
			}
		}
	}


/**
 * index method
 *
 * @return void
 */
	public function index() {
		$this->Usuario->recursive = 0;
		$this->set('usuarios', $this->paginate());
	}

/**
 * view method
 *
 * @param string $id
 * @return void
 */
	public function view($id = null) {
		$this->Usuario->id = $id;
		if (!$this->Usuario->exists()) {
			throw new NotFoundException(__('Invalid usuario'));
		}
		$this->set('usuario', $this->Usuario->read(null, $id));
	}

/**
 * add method
 *
 * @return void
 */
	public function add() {
		if ($this->request->is('post')) {
			$this->Usuario->create();
			if ($this->Usuario->save($this->request->data)) {
				$this->Session->setFlash(__('The usuario has been saved'));
				$this->redirect(array('action' => 'index'));
			} else {
				$this->Session->setFlash(__('The usuario could not be saved. Please, try again.'));
			}
		}
		$grupos = $this->Usuario->Grupo->find('list');
		$this->set(compact('grupos'));
	}

/**
 * edit method
 *
 * @param string $id
 * @return void
 */
	public function edit($id = null) {
		$this->Usuario->id = $id;
		if (!$this->Usuario->exists()) {
			throw new NotFoundException(__('Invalid usuario'));
		}
		if ($this->request->is('post') || $this->request->is('put')) {
			if ($this->Usuario->save($this->request->data)) {
				$this->Session->setFlash(__('The usuario has been saved'));
				$this->redirect(array('action' => 'index'));
			} else {
				$this->Session->setFlash(__('The usuario could not be saved. Please, try again.'));
			}
		} else {
			$this->request->data = $this->Usuario->read(null, $id);
		}
		$grupos = $this->Usuario->Grupo->find('list');
		$this->set(compact('grupos'));
	}

/**
 * delete method
 *
 * @param string $id
 * @return void
 */
	public function delete($id = null) {
		if (!$this->request->is('post')) {
			throw new MethodNotAllowedException();
		}
		$this->Usuario->id = $id;
		if (!$this->Usuario->exists()) {
			throw new NotFoundException(__('Invalid usuario'));
		}
		if ($this->Usuario->delete()) {
			$this->Session->setFlash(__('Usuario deleted'));
			$this->redirect(array('action' => 'index'));
		}
		$this->Session->setFlash(__('Usuario was not deleted'));
		$this->redirect(array('action' => 'index'));
	}
}