This site is running on Drupal 7, which is an awesome piece of free software. Drupal 7 is still in beta, and many of the modules contributed modules used to give basic functionality to the site are still in beta too.
The last (beta3 - final) version of Drupal has fixed the 5 remaining important security and critical known issues, but in doing so, it has broken a few of the modules essential for the site to function. Luckily, the maintainer of those modules is Aquia (the company of the founder of Drupal) who is using those on their own websites (actually: having those modules working is a basic need for their core business operations). This means a new unbroken version of the modules should be soon available.