CI crashes only on home page

So, had the site fully operational on a subdomain on the server (beta.site.com)

Moved the beta to the public_html folder (renaming folders and all)

The site's pages work just fine:
http://www.stoneworkbygarethjordan.com/m...t_list_art
Index page will work:
http://www.stoneworkbygarethjordan.com/index.php
But without the index.php, it won't:
http://www.stoneworkbygarethjordan.com/

So, first made sure I had the right php (I do)
http://www.stoneworkbygarethjordan.com/phpinfo.php

Checked the config.php file to make sure the data is correct:

PHP Code:

$config['base_url'] = 'http://www.stoneworkbygarethjordan.com/';
$config['index_page'] = '';
$config['uri_protocol'] = 'REQUEST_URI'; 


Then tried a zillion different htaccess changes from the default.

PHP Code:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L] 


to

PHP Code:

<IfModule mod_rewrite.c>
Options +FollowSymLinks -Indexes
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# deal with php5-cgi first
<IfModule mod_fcgid.c>
RewriteRule ^(.*)$ index.php?/$1 [QSA,L]
</IfModule>

<IfModule !mod_fcgid.c>

# for normal Apache installations
<IfModule mod_php5.c>
RewriteRule ^(.*)$ index.php/$1 [QSA,L]
</IfModule>

# for Apache FCGI installations
<IfModule !mod_php5.c>
RewriteRule ^(.*)$ index.php?/$1 [QSA,L]
</IfModule>

</IfModule> 
</IfModule> 


(with tons of iterations between)

I also changed the uri_protocol in config to everything listed (and AUTO because nothing else was working)
I'm on bluehost, I'm at a loss as to why this worked on the very same server under the beta subdomain (without needing the index.php for the home page) and I move it and now it blows up.  

What (stupidly obvious) thing am I missing?

(just for completeness, I reset the beta folder and uploaded the files for the home page - which you can see here - http://beta.stoneworkbygarethjordan.com/ - same htaccess, config, server, etc - works)