Add custom fields into Feedburner feed

Hi!

I have a client with the blog at http://artpartner.com/news/
The images on this blog come from Custom fields.

The question is – how can I display those images in feedburner feed?

I tried RSS Custom Fields, RSS Manager, WP RSS Images plugins. I also tried to add the following code (found somewhere on the web) into functions file:

// ADD CUSTOM POST TYPES TO RSS FEED //

function add_cpts_to_rss_feed( $args ) {
  if ( isset( $args['feed'] ) && !isset( $args['post_type'] ) )
    $args['post_type'] = array('post', 'results');
  return $args;
}

add_filter( 'request', 'add_cpts_to_rss_feed' );
//flush();

// ADD CUSTOM FIELDS TO FEED
function meko6_postrss($content) {
global $wp_query;
$postid = $wp_query->post->ID;
$img = get_post_meta($postid, 'img', true);
$img1 = get_post_meta($postid, 'img1', true);
if(is_feed()) {
	if($img !== '') {
	$content = "<img src='".$img."' style='float:left;'>".$content;
	}
	elseif($img1 !== '') {
	$content = "<img src='".$img1."' style='float:left;'>".$content;
	}
	else {
	$content = $content;
	}
}
return $content;
}
add_filter('the_excerpt_rss', 'meko6_postrss');
add_filter('the_content', 'meko6_postrss');

The code is not working as well, but I suspect the reason might be because the posts come from custom post types. Could anyone give me some tips on how could I modify the code so it would work with custom post types?