WordPress MU

I'm using WPMU set up as subdirectories instead of as subdomains ("VHOST" is set to "NO" in wp-config.php). My problem is that real subdomains are being interpreted as non-existent MU blogs. For example, if I go to "subdomain.domain.com", it resolves as "domain.com/wp-signup.php?new=" and displays the "Registration is disabled" message instead of the contents of the subdomain, which currently has static html files.

With WPMU installed in the root of my domain, is there something else I need to do to turn off this url rewriting?

Please do a search for 'previous subdomains' as it's been discussed a number of times.

Thanks for the search tip. Adding these lines to .htaccess solved my problem;

RewriteCond %{HTTP_HOST} subdomain.maindomain.com
RewriteCond %{REQUEST_URI} !subdomain/
RewriteRule ^(.*)$ subdomain/$1 [L]

I have same situation;
I have added in .htaccess
RewriteCond %{HTTP_HOST} subdomain.maindomain.com
RewriteCond %{REQUEST_URI} !subdomain/
RewriteRule ^(.*)$ subdomain/$1 [L]

still its not loading, instead going to singup page.
if i setup as redirect
eg: http://abio.mynation.net > http://mynation.net/abio that works.

but i do not want to show actual path as http://mynation.net/abio when people enter from http://abio.mynation.net should stay on same URL.

is there any solution.

if i setup other directory, http://mynation.net/test/ and creat subdomain http://test.mynation.net it works. and stay on same URL. but MU blog directory is virtual so it endup in signup page.

what to do