Index: db/models/fields/related.py
===================================================================
--- db/models/fields/related.py	(revision 8066)
+++ db/models/fields/related.py	(working copy)
@@ -704,7 +704,8 @@
     """
     def __init__(self, to, to_field=None, **kwargs):
         kwargs['unique'] = True
-        kwargs['editable'] = False
+        if kwargs.get('parent_link', False):
+            kwargs.setdefault('editable', False)
         if 'num_in_admin' not in kwargs:
             kwargs['num_in_admin'] = 0
         super(OneToOneField, self).__init__(to, to_field, OneToOneRel, **kwargs)