Index: wp-includes/comment-functions.php
===================================================================
--- wp-includes/comment-functions.php	(revision 3246)
+++ wp-includes/comment-functions.php	(working copy)
@@ -308,7 +308,7 @@
 		if (!empty($CSSclass)) {
 			echo ' class="'.$CSSclass.'"';
 		}
-		echo ' title="' . sprintf( __('Comment on %s'), $post->post_title ) .'">';
+		echo ' title="' . sprintf( __('Comment on %s'), wptexturize($post->post_title) ) .'">';
 		comments_number($zero, $one, $more, $number);
 		echo '</a>';
 	}