[Plugin: Simple Facebook Comments For WordPress] Not Work On my site

I used wordpress 3.2.1 and error for activate this plugin:
Plugin could not be activated because it triggered a fatal error
Fatal error: Class ‘PDO’ not found in /home/xxxxx/public_html/subdomain/xxxxxx.com/wp-content/plugins/simple-facebook-comments-for-wordpress/Model/PdoSingleton.php on line 10

Is this bug for this version of plugin?
Anyone can help me?

Thanks before.

https://www.ads-software.com/extend/plugins/simple-facebook-comments-for-wordpress/