This isn't a bug, just a bit of a technical issue for me. When I'm on Adventure Cow and click the "Write a Story" tab, I see a list of the stories I'm working on. If I click the title of one of these stories, I get the main page for the story. But if on this page I click Play Story, and my story is private, it will say I don't have permission to see this page -- or something to that effect.
This is because that is the main page from which anyone can play your game, but it'd be nice if the site recognized that it was me so that I could play the game from the beginning at that link instead of navigating to Start in the editor...