CakePHP 2.0 - Able to Register, but cannot login - cakephp

Question

Im CakePHP newbie, apologies if the question has been asked i search it but could not find. I have problem with the code below. It works well when it i register new user, problem when im trying to login i get and error "Invalid username or password'); Please help
public function login() {
if ($this->request->is('post')) {
if ((!empty($this->request->data['User']) && $this->Auth->login())) {
$this->Session->setFlash(__('Welcome, '. $this->Auth->user('username')));
$this->redirect($this->Auth->redirectUrl());
} else {
$this->Session->setFlash(__('Invalid username or password'));
}
}
}
//******* LOGIN CTP************
<div class="users form">
<?php echo $this->Session->flash('auth'); ?>
<?php echo $this->Form->create('User'); ?>
<fieldset>
<legend><?php echo __('Please enter your username and password'); ?></legend>
<?php echo $this->Form->input('username');
echo $this->Form->input('password');
?>
</fieldset>
<?php echo $this->Form->end(__('Login')); ?>
//*******************BEFORE SAVE *************************
public function beforeSave($options = array()) {
// hash our password
if (isset($this->data[$this->alias]['password'])) {
$this->data[$this->alias]['password'] = AuthComponent::password($this->data[$this->alias]['password']);
}
// if we get a new password, hash it
if (isset($this->data[$this->alias]['password_update']) && !empty($this->data[$this->alias]['password_update'])) {
$this->data[$this->alias]['password'] = AuthComponent::password($this->data[$this->alias]['password_update']);
}
// fallback to our parent
return parent::beforeSave($options);
}