First of all we are really sorry for the inconvenience caused with this plugin update.
We already uploaded a fixed version of the plugin which can be downloaded from: http://downloads.wordpress.org/plugin/secure-wordpress.2.0.3.zip.
If you have problems accessing your blog because of the plugin update, simply login via FTP or your host's control panel and delete the plugin directory. The default plugin directory can be found in /wp-content/plugins/ WordPress sub directory.
While hoping you find this plugin useful, feel free to post any queries or suggestions you might have on the WebsiteDefender forums; http://www.websitedefender.com/forums.
Looking forward to hearing from you.
Technical Manager - WebsiteDefender