Hi,
Did you set "encoding:" to database.yml ?
(e.g.) development: adapter: mysql database: depot_development socket: /var/lib/mysql/mysql.sock username: foo password: bar encoding: cp932
cp932 is a subset of shift jis on Windows. "utf8" may be better with Rails.
And also you need to set Content-Type correctly. http://nubyonrails.com/articles/2006/02/01/rjs-and-content-type-header
