Very odd. I have a custom menu created for a child theme of TwentyEleven. I have added a bunch of pages and arranged them as I see fit. It works.
I want to add a custom link with a generic title so I can put three pages under it as sub-pages. But when I enter the name of the custom link and click "Add to Menu" nothing happens.
The funny thing is that I've done this before on a couple other sites and it has worked. Am I missing something here? I even went to a site I developed and tried to add more custom links to that site than the ones I already added, and they won't add. ???