Since only a few are having problems with it, it's probably a setting on your local machine. From the source code, the Chatter Box appears to be a javascript module which is not rendering on your computer. If you're using IE9, try viewing the web site in compatibility mode. Next to the URL there should be a what looks like a little circle icon pointing to the right and just before that, the compatibility icon which looks like a little piece of paper torn in half - just click it. If the icon's not there, have the web site open in IE and press Alt T and the tools menu will drop down. Click the compability button and add XI, then click the icon when it shows up in the browser.
Sometimes, when javascript fails in IE, it loads OK in a mozilla-based browser like Firefox.