Index: wp-includes/feed-atom-comments.php
===================================================================
--- wp-includes/feed-atom-comments.php	(revision 21356)
+++ wp-includes/feed-atom-comments.php	(working copy)
@@ -20,7 +20,7 @@
 		elseif ( is_search() )
 			printf( ent2ncr( __( 'Comments for %1$s searching on %2$s' ) ), get_bloginfo_rss( 'name' ), get_search_query() );
 		else
-			printf( ent2ncr( __( 'Comments for %s' ) ), get_bloginfo_rss( 'name' ) . get_wp_title_rss() );
+			printf( ent2ncr( __( 'Comments for %s' ) ), get_wp_title_rss() );
 	?></title>
 	<subtitle type="text"><?php bloginfo_rss('description'); ?></subtitle>
 
Index: wp-includes/feed-atom.php
===================================================================
--- wp-includes/feed-atom.php	(revision 21356)
+++ wp-includes/feed-atom.php	(working copy)
@@ -16,7 +16,7 @@
   xml:base="<?php bloginfo_rss('url') ?>/wp-atom.php"
   <?php do_action('atom_ns'); ?>
  >
-	<title type="text"><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
+	<title type="text"><?php wp_title_rss(); ?></title>
 	<subtitle type="text"><?php bloginfo_rss("description") ?></subtitle>
 
 	<updated><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></updated>
Index: wp-includes/feed-rdf.php
===================================================================
--- wp-includes/feed-rdf.php	(revision 21356)
+++ wp-includes/feed-rdf.php	(working copy)
@@ -19,7 +19,7 @@
 	<?php do_action('rdf_ns'); ?>
 >
 <channel rdf:about="<?php bloginfo_rss("url") ?>">
-	<title><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
+	<title><?php wp_title_rss(); ?></title>
 	<link><?php bloginfo_rss('url') ?></link>
 	<description><?php bloginfo_rss('description') ?></description>
 	<dc:date><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></dc:date>
Index: wp-includes/feed-rss.php
===================================================================
--- wp-includes/feed-rss.php	(revision 21356)
+++ wp-includes/feed-rss.php	(working copy)
@@ -11,7 +11,7 @@
 echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
 <rss version="0.92">
 <channel>
-	<title><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
+	<title><?php wp_title_rss(); ?></title>
 	<link><?php bloginfo_rss('url') ?></link>
 	<description><?php bloginfo_rss('description') ?></description>
 	<lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
Index: wp-includes/feed-rss2-comments.php
===================================================================
--- wp-includes/feed-rss2-comments.php	(revision 21356)
+++ wp-includes/feed-rss2-comments.php	(working copy)
@@ -23,7 +23,7 @@
 		elseif ( is_search() )
 			printf( ent2ncr( __( 'Comments for %1$s searching on %2$s' ) ), get_bloginfo_rss( 'name' ), get_search_query() );
 		else
-			printf( ent2ncr( __( 'Comments for %s' ) ), get_bloginfo_rss( 'name' ) . get_wp_title_rss() );
+			printf( ent2ncr( __( 'Comments for %s' ) ), get_wp_title_rss() );
 	?></title>
 	<atom:link href="<?php self_link(); ?>" rel="self" type="application/rss+xml" />
 	<link><?php (is_single()) ? the_permalink_rss() : bloginfo_rss("url") ?></link>
Index: wp-includes/feed-rss2.php
===================================================================
--- wp-includes/feed-rss2.php	(revision 21356)
+++ wp-includes/feed-rss2.php	(working copy)
@@ -21,7 +21,7 @@
 >
 
 <channel>
-	<title><?php bloginfo_rss('name'); wp_title_rss(); ?></title>
+	<title><?php wp_title_rss(); ?></title>
 	<atom:link href="<?php self_link(); ?>" rel="self" type="application/rss+xml" />
 	<link><?php bloginfo_rss('url') ?></link>
 	<description><?php bloginfo_rss("description") ?></description>
Index: wp-includes/feed.php
===================================================================
--- wp-includes/feed.php	(revision 21356)
+++ wp-includes/feed.php	(working copy)
@@ -83,6 +83,8 @@
 	$title = wp_title($sep, false);
 	if ( is_wp_error( $title ) )
 		return $title->get_error_message();
+	if ( false === strpos( $title, get_bloginfo_rss( 'name' ) ) )
+		$title = get_bloginfo_rss( 'name' ) . $title;
 	$title = apply_filters('get_wp_title_rss', $title);
 	return $title;
 }