the pdo-exstesion is related to php ini is a extension not a installation related to the site!
you must asking to x10 if they answer.
Pdo extension is a base for drupal...
So chomel you don't know that?
anyway try that but generally don't work if pdo-extensions related to php to server side isn't enabled
http://drupal.org/node/914106
chomel instead give this false information isn't better before to check what is a pdo-extension?