I am also running PHP 5.2.17 on my web site. A 500 Error means the web server has failed which usually means some sort of internal PHP error. Do you know what platform your site is running on? I am running under Linux with Apache with MySQL 5.0 and PHP 5.2.17.
If you want me give me access to your Dashboard I would be happy to take a look. I am not sure what else to suggest at this point. There isn't any unusual PHP in the plugin that I am aware of.