set_value不起作用

I have the form_validation library loaded in my controller and the form validation itself is working, but when using set_value() it's not populating the form fields. Here is the code in to controller:

function addUser()
{
    $this->form_validation->set_rules('firstName', 'firstname', 'trim|required|max_length[30]');
    $this->form_validation->set_rules('surname', 'surname', 'trim|required|max_length[30]');
    $this->form_validation->set_rules('emailAddress', 'email address', 'trim|required|valid_email|is_unique[users.email]|max_length[255]');
    $this->form_validation->set_rules('password', 'password', 'trim|required|max_length[20]|min_length[5]');
    $this->form_validation->set_rules('passwordVerify', 'password verification', 'trim|required|max_length[20]|min_length[5]');

    if($this->form_validation->run() === FALSE) {
        $this->session->set_flashdata('formValidationError',  validation_errors('<p class="error">', '</p>'));
        redirect('/member/register');
    } else {
        echo 'Passed';
    }
}

And here is the code in the view:

    <?php echo $this->session->flashdata('formValidationError'); ?>
<form method="POST" action="<?php echo site_url('member/addUser'); ?>">
    <fieldset>
        <legend>Create a FREE account</legend>
        <div>
            <label for="firstName">Firstname</label>
            <input type="text" name="firstName" value="<?php echo set_value('firstName'); ?>" maxlength="30">
        </div>

        <div>
            <label for="surname">Surname</label>
            <input type="text" name="surname" value="<?php echo set_value('surname'); ?>" maxlength="30">
        </div>

        <div>
            <label for="emailAddress">Email Address</label>
            <input type="text" name="emailAddress" value="<?php echo set_value('emailAddress'); ?>" maxlength="255">
        </div>

        <div>
            <label for="password">Password</label>
            <input type="password" name="password" maxlength="20">
        </div>

        <div>
            <label for="passwordVerify">Verify Password</label>
            <input type="password" name="passwordVerify" maxlength="20">
        </div>

        <button type="submit">Register</button>
    </fieldset>
</form>

Is there something I am missing? Is the redirect causing the issue?