Whilst the AppThemes demo site is fully functional, you cannot save data to it, which is why certain aspects do not work as they do in a normal installation (there should have been a pop up message outlining this when you first visited the demo site).
We appreciate the feedback about the sites on the showcase, these were originally submitted by members of our community, and we're not always updated when they make changes to their sites so we will be reviewing these asap. Thanks.