WordPress MU

I currently have my MU subdomain install working out of one location, but I want to move the core to a different subdomain, so that people could login at a different address, like this:

Main site: http://domain.org
Core/backend: http://backend.domain.com

I tried setting the WP_HOME and WP_SITE_URL in the config.php file and using .htaccess to set a subdomain. It seems that it works (content would appear), until I try to log in to the backend, then it tries to create a new subdomain with the "backend" address. MU seems to not understand that backend.domain.com is a not a new site, but rather the core file's home. The reason I wanted to do this is to move some other installs (MediaWiki, etc.) into the main site's directory.

Do a search for "previous subdomain" as we've discussed it at some length in the past. You have to add the subdomain name to your block list within wpmu as well as add some lines to htaccess to forward requests past wpmu to the stand alone.

that was my first search before posting this. for some reason, that redirect does not work.