UTF8 Sanitize Plugin

This plugin is designed to “fight” the broken UTF8
characters on your WordPress powered site.

Install the UTF8 Sanitize WordPress plugin and you
will be able to fight those ugly characters. Additionally, you can customize
what actions you want to perform on them – either convert them to their original
values once and for all by modifing your posts’ database, OR leave all
your posts intact and instead convert the ugly chars each time a post is loaded
(all these options are controlled from the WordPress admin panel).