--- og_user_roles.module
+++ (clipboard)
@@ -920,8 +920,8 @@
   $data['og_users_roles']['table']['group']  = t('OGUR Groups');
   $data['og_users_roles']['table']['join'] = array(
     'node' => array(
-      'left_field' => 'gid',
-      'field' => 'nid',
+      'left_field' => 'nid',
+      'field' => 'gid',
     ),
     'users' => array(
       'left_field' => 'uid',