Index: pluggable-functions.php
===================================================================
--- pluggable-functions.php	(revision 2925)
+++ pluggable-functions.php	(working copy)
@@ -222,8 +222,10 @@
 	$comment = $wpdb->get_row("SELECT * FROM $wpdb->comments WHERE comment_ID='$comment_id' LIMIT 1");
 	$post = $wpdb->get_row("SELECT * FROM $wpdb->posts WHERE ID='$comment->comment_post_ID' LIMIT 1");
 
-	if ('' == $user->user_email) return false; // If there's no email to send the comment to
+	$user = new WP_User($post->post_author);
 
+	if ('' == $user->data->user_email) return false; // If there's no email to send the comment to
+
 	$comment_author_domain = gethostbyaddr($comment->comment_author_IP);
 
 	$blogname = get_settings('blogname');
@@ -271,7 +273,7 @@
 	$subject = apply_filters('comment_notification_subject', $subject);
 	$message_headers = apply_filters('comment_notification_headers', $message_headers);
 
-	@wp_mail($user->user_email, $subject, $notify_message, $message_headers);
+	@wp_mail($user->data->user_email, $subject, $notify_message, $message_headers);
    
 	return true;
 }