If you have a content type with a required Boolean field and try to create a new content object without the field checked, you will receive an *required field* error message.
After that message, even if you mark the Boolean field as checked, the admin interface won't let you to publish the draft. The publish button will be simply disabled.
- Create a content type with a checkbox field and make it required
- Create a new content of this type and do not check the checkbox and click save
- You will receive an *required field* error message
- Check the checkbox and click save/publish and see that it is not working.