I am the official developer.
I checked your site, and it looks like you may have: weirdly configured PHP (could you set up a PHPINFO file for me to look at?), and no mod_rewrite.
Mod_rewrite is an apache module, I know for a fact it comes with the default installation of Apache 1.3, but I noticed you are using Apache 2.0, which I have no experience with. If you installed the server yourself, look into
this. Otherwise, you will have to contact your webhost.
Also, to make a PHPINFO file, just make an empty file, call it phpinfo.php, and put inside it:
<?php phpinfo(); ?>
Good Luck
Lappy512