Hi!
Checking the console an error appears that says “Widget configuration is not found” which means that the widget ID you’re using might be invalid. Could you please go back to the configuration page on https://twitter.com/settings/widgets and copy the embed code anew?
We’ve fixed quite a lot of the MooTools conflict problems this week so hopefully that won’t be a cause of problems any more, but on your site there is the configuration error. Try pasting the widget again and that should set you straight.
Thanks,
Ben