http://shield.network12.net/index.php?ID=559Test works fine, however 559Test does not.
This indicates there is a problem with re-writing URLs. Is .htaccess present in the Link Protector's root directory, and without modification? Nevertheless, download Daddy's Link Protector again and re-upload (replace) .htaccess under DLP's root with the one present in the ZIP file.
If you still encounter issues, I assume your server does not have mod_rewrite installed or it is not active. Please seek further advise from your web hoster in regards to this issue.