Links between slides don't work in PowerPoint HTML
When you Save as HTML or Publish as Web Page from PowerPoint 2000, 2002 or 2003, links between slides, such as the slide links in the Table of Contents frame, don't work in the browser.
These HTML links may work on the system where you publish to HTML, but they fail when you move the html files to a different folder or publish them to your web site.
Choose File, Properties and on the Summary tab, select and delete any text in the "Hyperlink base" text field.
Save your presentation and Publish to Web again. The slide links in the table of contents should now be path free, so the links will work no matter where you put the HTML files, so long as the main HTML file and all supporting files stay together.