Without getting into the gory details (unless you want me to) the theme you're using is not following best practices with regards to jQuery, and it appears to be causing conflicts with your plugins. It's the likely reason you're having issues with both my plugin and the WordPress Post Tabs plugin as well.
Easy way to fix this is to switch themes. The harder way (if you lack the skills in php) is to try to fix the conflict yourself. If that's the path you want to take, I can provide a little guidance if you need help.