Index: comment-functions.php
===================================================================
--- comment-functions.php	(revision 2953)
+++ comment-functions.php	(working copy)
@@ -38,6 +38,7 @@
 	$commentdata['comment_agent'] = $_SERVER['HTTP_USER_AGENT'];
 	$commentdata['comment_date'] = current_time('mysql');
 	$commentdata['comment_date_gmt'] = current_time('mysql', 1);
+	$commentdata['user_ID'] = (int) $commentdata['user_ID'];
 
 	$commentdata = wp_filter_comment($commentdata);
 
@@ -50,8 +51,10 @@
 	if ( 'spam' !== $commentdata['comment_approved'] ) { // If it's spam save it silently for later crunching
 		if ( '0' == $commentdata['comment_approved'] )
 			wp_notify_moderator($comment_ID);
-	
-		if ( get_settings('comments_notify') && $commentdata['comment_approved'] )
+
+		$post = &get_post($commentdata['comment_post_ID']);
+
+		if ( get_settings('comments_notify') && $commentdata['comment_approved'] && $post->post_author != $commentdata['user_ID'] )
 			wp_notify_postauthor($comment_ID, $commentdata['comment_type']);
 	}