Have problems with code please help?

[eluser]gork7478[/eluser]
I have a problem that I really hope someone can help me with. In my model I have this code the get hashed password from database.

Code:

public function getPasswordHash($email) {
        $sql = 'SELECT `password` FROM users WHERE email=? LIMIT 1';
        $query = $this -> db -> query($sql, array($email));

        return ($query -> num_rows() > 0) ? $query -> row() : FALSE;
    }

Now I have a callback function that I'm trying to run to compared password in controller here's the code for that.

Code:

function _checkPassword($pass)
    {
        $hasher = new PhpAss();
        $this->load->model('user');
        $hashed_pass = $this->user->getPasswordHash($this->input->post('email'));
        $hashed_pass = $hashed_pass->password;

        if ($hasher->checkPassword($pass, $hashed_pass))
        {
            echo 'true';
        }
        else
        {
            $this->form_validation->set_message('_checkPassword', 'The Email and/or Password is incorrect. Please try again');
            return false;
        }
    }

A PHP Error was encountered

Severity: Notice

Message: Trying to get property of non-object

Filename: controllers/main.php

Line Number: 149

And this is the error I'm getting when I put the wrong password in my form. If I put the correct password it works. Any help would be greatly appreciated.