Hi,

  If you're wanting to create a fresh install of a Magnum based site into your pre-existing multi site, here are a few lessons learned:

1.  Be sure to put the mdmagnum directory that you get when you unzip md_magnum_install_profile.zip  file into your multisites profiles directory.  I made the mistake of putting the md-magnum directory into my profiles/ directory and while mdmagnum shows up as an install option, it won't go in as mdmagnum has a full drupal 7 release in it already.  For example:

unzip md_magnum_install_profile.zip

cd md-magnum

cd profiles

cp -p -r mdmagnum /var/www/drupal7/profiles

2.  Figure out which modules you're missing from your current install and put them into your modules folder.  This example assumes you don't distinguish between contrib and custom modules with different directories.

cd md-magnum/sites/all/modules/contrib

cd ..

diff contrib /var/www/drupal7/sites/all/modules | grep contrib

#use Drush to download missing modules as listed when you run this command directed at your module directory., or copy from profile directory over and update later.  Then, copy the custom modules over.

cp -p -r custom/* /var/www/drupal7/sites/all/modules

#Go through the installation process from the web to install the Magnum profile

#Run these sql commands:

UPDATE system SET filename = replace(filename,'modules/contrib','modules');

UPDATE registry SET filename = replace(filename,'modules/contrib','modules');

UPDATE registry_file SET  filename = replace(filename,'modules/contrib','modules');

#Clear Caches  (I use drush cc to do this)

# I found that for whatever reason the media_filter_usage table didn't get created:

CREATE TABLE `media_filter_usage` (
`fid` INT( 10 ) UNSIGNED NOT NULL DEFAULT  '0',
 `timestamp` INT( 11 ) NOT NULL DEFAULT  '0'
) ENGINE = INNODB DEFAULT CHARSET = latin1;

Hope this helps.