[support] Drupal 7 Multisites problem somewhere?

[Unknown]

I have Fedora 14,
fresh installation of Drupal 7beta3 in it's own mysql database
I set up new mysql 'site' database.

Firefox http://localhost/drupal7b3 dispalys but  
http://localhost/site_au shows "Not Found" the requested url was not  
found on this server.

Seems that Drupal 7 is not seeing the new directory

/etc/hosts has 127.0.0.1 site_au.org  localhost

/etc/httpd/conf/httpd.conf has:
NameVirtualHost *:80
###----------------------drupal au site-----#
<VirtualHost *:80>
     DocumentRoot "/var/www/html"
     ServerAdmin webmaster at localhost
     ServerName site_au.org:80
     ErrorLog logs/site_au.org-error_log
     CustomLog logs/site_au.org-access_log common
</VirtualHost>

As per tutorial the new site is /drupal7/sites/site_au.org

/drupal7/sites/sites.php has:
$sites['localhost.site_au'] = 'site_au';

settings.php is a copy of /sites/default/settings.php and is in the  
folder drupal7/sites/site_au.org

/var/log/httpd/site_au.org-error_log reports:
[Sat Apr 09 15:27:38 2011] [error] [client 127.0.0.1] File does not  
exist: /var/www/html/site_au
[Sat Apr 09 15:30:15 2011] [error] [client 127.0.0.1] File does not  
exist: /var/www/html/drupal7/site_au

  What have I overlooked or done incorrectly please
Help much appreciated
Roger