Some troubleshooting ideas:
* In Firebug (a free extension you install for Firefox), open the "Net" panel and reload the page -- see if it reports anything that can't be loaded.
* Also in Firebug, open the "Console" panel and see if it reports any javascript errors.
* Try different browsers (Chrome, Firefox, Safari, IE if you're on Windows) and see if that makes any difference.
* See if it depends on whether you're logged into the site or not.

Thank you. It doesn't seem to matter if I'm signed in or not. Sometimes it loads, sometimes it doesn't. I installed Firebug and loaded it with the Net tab and the Console tab and neither threw any errors. Right now it's not loading in IE, FF, or Chrome.

It seems I have to go into the slideshow element and republish it, and then it shows up.