Index: wp-includes/comment.php
===================================================================
--- wp-includes/comment.php	(revision 15591)
+++ wp-includes/comment.php	(working copy)
@@ -588,7 +588,7 @@
 			$approved = 'spam';
 	}
 
-	$approved = apply_filters('pre_comment_approved', $approved);
+	$approved = apply_filters( 'pre_comment_approved', $approved, $commentdata );
 	return $approved;
 }