problem when i log out/in

Im just setting up my first fusion 6 site and have 2 problems.
First im getting a message that appears at the top of the screen when ever i log in or out as, it says

"Notice: Undefined index: user_name in E:\domains\e\energizedsoundsystem.co.uk\user\htdocs\themes\Revision\theme_config.php on line 43"

the theme_config.php file is:

<?php
if (!defined("IN_REVISION") { header("Location: ../../index.php"; exit; }
/*--------------------------------------------+
| PHPFusion v6 - Content Management System |
|---------------------------------------------|
| author: Nick Jones (Digitanium) © 2002-2005 |
| web: http://www.php-fusion.co.uk |
| email: nick@php-fusion.co.uk |
|---------------------------------------------|
| Released under the terms and conditions of |
| the GNU General Public License (Version 2) |
+--------------------------------------------*/
/*--------------------------------------------+
| Revision Theme for PHPFusion v6 |
|---------------------------------------------|
| author: UworldIRC - Riadi © 2006 |
| web: http://www.uworldirc.com/ |
| email: riadi@gcinet.org |
|---------------------------------------------|
| Released under the terms and conditions of |
| the GNU General Public License (Version 2) |
+--------------------------------------------*/

/* PHP Fusion theme default configurations */
$body_text = "#444444";
$body_bg = "#DAE2E3";
$theme_width = 900;
$theme_panels_exclude = array("/forum/";

$theme_panels_width = 170;
// keep the width of the panels the same so it does not compress the tables
$theme_width_r = $theme_panels_width;
$theme_width_l = $theme_panels_width;


/* Revision Theme configurations */
# for support and explanation about these configurations please go to http://www.uworldirc.com/support/revision

// Page Header
$rtHeader['logo_url'] = BASEDIR.'index.php';
$rtHeader['logo_url_title'] = 'Front Page';

$rtHeader['rightside_member'] = "Welcome <strong>".$userdata['user_name']."</strong>";
$rtHeader['rightside_guest'] = "Welcome <strong>Guest</strong><br>please <a href='".BASEDIR."login.php'>login</a> or <a href='".BASEDIR."register.php'>register</a>";


// Navigation Bar
$rtNavbar->newmenu('Home','Home';
$rtNavbar->submenu('Home', 'Front Page', 'index.php', 1);


$rtNavbar->newmenu('Equipment','Equipment';
$rtNavbar->submenu('Sound', 'Sound', 'contact.php', 0);
$rtNavbar->submenu('Lighting', 'Lighting', 'forum/index.php', 0);

$rtNavbar->newmenu('Services','Services';
$rtNavbar->submenu('Repair', 'Repair', 'members.php', 1);
$rtNavbar->submenu('Rental', 'Rental', 'members.php', 1);

$rtNavbar->newmenu('Gallery','Gallery';
$rtNavbar->submenu('System Pictures', 'System Pictures', 'members.php', 1);
$rtNavbar->submenu('Events', 'Events', 'members.php', 1);

$rtNavbar->newmenu('Events','Events';
$rtNavbar->submenu('Events', 'Events', 'members.php', 1);

if (iMEMBER) {
$rtNavbar->newmenu('member','member';
$rtNavbar->submenu('View Profile', 'View your profile', 'profile.php?lookup='.$userdata['user_id'], 0);
$rtNavbar->submenu('Edit Profile', 'Edit your profile', 'edit_profile.php', 1);
$rtNavbar->submenu('Private Messages', 'View your private messages', 'messages.php', 1);
$rtNavbar->submenu('Logout', 'Logout', 'setuser.php?logout=yes', 0);
$rtNavbar->submenu('Administration','Administration';
} else {
$rtNavbar->submenu('Login', 'Login', 'login.php', 0);
$rtNavbar->submenu('Register', 'Register an Account', 'register.php', 0);
}

if ((iADMIN) && ($userdata['user_rights'] != "") {
$rtNavbar->newmenu('Administration','Administration';
$rtNavbar->submenu('Control Panel', 'Control Panel', 'administration/index.php'.$aidlink, 0);

}
?>

has any body seen this before, its happened since i set up the site?
Also, not sure if its related, but it takes ages to log in or out (minutes), seems to hang but then works. also it takes a minute to get the menu/nav drop downs to work?
the old site im still running on the same server is quick!

Any one please??