Multisite installation 500 error

Hello,

I’m trying to run wordpress multisite (on bluehost). On that server I already have a few wordpress installations (e.g. ~/public_html/accorda and ~/public_html/socialfeel-net. The ~/public_html/.htaccess contains:
`
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
# if I turn off the following rule I stop getting 500 on
# space.socialfeel.net/wp-admin/ but I still get 404
# but then permalinks on accorda stop working
# (http://accorda-institute.org/research/)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
`

And the ~/public_html/social_feel-net/.htaccess contains:
`
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteRule ^index\.php$ – [L]
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ – [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]
</IfModule>
`

When I try to open wp-admin page of a created new subdomain (from wp-admin > my-sites > subdomain > dashboard) I always get 500 error message. The server log sais Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace., referer: http://socialfeel.net/wp-admin/my-sites.php

If I remove rules from ~/public_html/.htaccess apart from that permalinks on accorda stop working I am getting 404 error message on socialfeel.net. The error message shows then:
`
File does not exist: /home1/accordai/public_html/wildcard/wp-admin, referer: http://socialfeel.net/wp-admin/my-sites.php
`

The file indeed does not exist, and the server is looking for it in a wrong directory.

Thanks for ideas how to fix this.