cannot set nodereference field to "required"

Here is what is happening ...

Scenario #1
-- create a parent node type, "parent"
-- create a child node type, "child"
-- add a nodereference field, "childptr", to the "parent" node-type.
---- Set the widget type to "node widget: create and reference".
---- Set the referenced-node type to "child".
---- Set the # of values to 1.
---- Leave the "required" checkbox unchecked.
This scenario works fine. I can create both the parent and child node from within the parent's node-edit form.

However ...

Scenario #2:
Same as above, except check the "required" checkbox.

Now, when I try to fill out and save the parent's node-edit form, I get this error message

"childptr field is required.
The settings have not been saved because of the errors."

That is, with the nodereference field marked "required", I am unable to create either parent or child nodes.