--- path_redirect.module	2010-02-14 12:38:38.000000000 -0800
+++ path_redirect.module	2010-02-14 12:38:03.000000000 -0800
@@ -311,6 +311,11 @@ function path_redirect_save($redirect) {
 
   path_redirect_clear_cache();
   
+  // See if there is an existing redirect.
+  if ($existing_redirect = path_redirect_load_by_source($redirect['source'])){
+    $redirect['rid'] = $existing_redirect['rid'];
+  }
+  
   if (empty($redirect['rid'])) {
     return drupal_write_record('path_redirect', $redirect);
   }