I can load "http://domain/_admin" and i get the 'login prompt, WITH the correct styles, and images (thats important).
but, when I enter root as user/pass, it says login incorrect.
Then, when I try "http://domain/mysource_matrix/_admin", I again get the login prompt, with the correct images and colors and styles. I enter "root" as user and pass, and it takes me to the admin control system… except… none of the styles are rendering, the java applet doesn't render, and none of the images are appearing.
experimenting I took a URL for one of the images…
"http://domain/mysource_matrix/__lib/web/images/tree/branch.gif" and removed the "mysource_matrix/" from the url giving me.
"http://domain/__lib/web/images/tree/branch.gif"
And, guess what, the image rendered.
here is my Virtualhost info for mysource. (I removed my domain name for a approximation of privacy… 
DocumentRoot /applications/web/mysource_matrix/core/web
ServerName domain.domain
Options Indexes FollowSymLinks
Order deny,allow
Deny from all
Options Indexes FollowSymLinks
Order allow,deny
Allow from all
Options Indexes FollowSymLinks
Order allow,deny
Allow from all
Options Indexes FollowSymLinks
Order allow,deny
Allow from all
Options Indexes FollowSymLinks
Order allow,deny
Allow from all
Alias "/__data" "/applications/web/mysource_matrix/data/public"
Alias "/__lib" "/applications/web/mysource_matrix/core/lib"
Alias "/__fudge" "/applications/web/mysource_matrix/fudge"
Alias "/" "/applications/web/mysource_matrix/core/web/index.php/"
(yes, I know its on port 8081, thats intentional)
any idea whats wrong?
Thank you.
Your VirtualHost sets up Matrix for the root of your domain, so your System Root URL has to match it. It should be (as you guessed) “