This logic, found in feed-rss2.php, is returning no results regardless of the state of "rss_use_excerpt".
<?php if (get_option('rss_use_excerpt')) : ?>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php else : ?>
<description><![CDATA[<?php the_excerpt_rss() ?>]]></description>
<?php if ( strlen( $post->post_content ) > 0 ) : ?>
<content:encoded><![CDATA[<?php the_content_feed('rss2') ?>]]></content:encoded>
<?php else : ?>
<content:encoded><![CDATA[<?php the_excerpt_rss() ?>]]></content:encoded>
<?php endif; ?>
<?php endif; ?>
see: http://www.allnineyards.com/?feed=rss2
"the_content_feed" and "the_excerpt_rss" return nothing.
If I modify feed-rss2.php to use "<?php the_content_rss() ?>" then the field is populated with the post's full text, but all internal links and image URLs are put in to footnotes with a "[1], [2}, [3], etc..." left in their original position.
This is causing rss readers and syndication systems to display those footnote indicators and ignore the images or URLs. GIGO, I can't change that behavior because the "make_url_footnote" function has been deprecated.