Sessions - Bug?

[eluser]amw_drizz[/eluser]
~Gah Rips hair out of head~

I have this issue!! Worked fine in CI 1.6.2 (before I updated straight to 1.7.0)

This is part of my login script This USED TO WORK but since I updated to 1.7.0 I have not been able to get it to work. I have even tried removing ALL output to the browser and I still get the same error. I am going to convert back to 1.6.2 since that did work. Hope that helps for code samples of causing an error

Error

Code:

A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at D:\WebServer\htdocs\xterm\system\application\main_site\controllers\auth.php:18)

Filename: libraries/Session.php

Line Number: 662

Code:

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class User_Control {
    function __construct(){
        $this->load->database();    
        $this->load->library('parser');
        $this->load->helper('url');
        $this->load->library('session');
        $this->load->library('user_agent');
        $this->load->library('validation');
        $this->load->library('encrypt');
        $this->load->library('email');
        //$this->load->library('themechooser');
        $this->load->helper(array('form', 'url'));
    }
    // Auth Segments
    function doLogin(){
        $rules['username'] = "callback_isreg|required|xss_clean";
        $rules['password'] = "required";
        $fields['username'] = "Username";
        $fields['password'] = "Password";
        $this->validation->set_fields($fields);
        $this->validation->set_rules($rules);
        $this->validation->set_error_delimiters('<div id="error" class="error">', '</div>');
        if($this->validation->run() == FALSE ){
            $this->load->view('auth/login');
        }
        else{
            $this->VerifyAuth();
        }
    }
    function VerifyAuth(){
        $post_array = array(
            'username' => $this->input->post('username', TRUE),
            'password' => md5($this->input->post('password')),
        );
        $query = $this->db->query("SELECT * FROM users WHERE username='". $post_array['username'] ."'");
        $row = $query->row_array();
        if($row['password'] !== $post_array['password']){
            /*
            This is/was for debugging to find out why passwords were not set right
            if($this->config->item('debug') == TRUE){
                echo "PWD in DB = ". $row['password'] ."\n";
                echo "PWD Received is ". $post_array['password'] ."\n";
            }
            else{ */
                //show_error('Incorrect Password Try again');
                $data['strike'] = 0;
                $data['limit'] = 0;
                echo $this->parser->parse("auth/invalid",$data,true);
            // }
        }
        elseif($row['active'] == 'no'){
            show_error('Your account is currently disabled,  Please contact the site Admin by <a href="'. site_url('messaging/unreg/admin') .'">Clicking here</a>');
        }
        else{
            $logged_array = array(
                            "username" => $row['username'],
                            "lvl" => $row['lvl'],
                            'uid' => $row['id'],
                            'loggedin' => TRUE,
                            );
            $this->session->set_userdata($logged_array);
            redirect('/members', 'refresh');
        }
    }

Maybe I am too stupid to get it working on 1.6.2 as well. But I do know it did work, but I am reworking the templating system on my site and it died on me.