code51 - 2010-08-15

Isn't this actually a Tomcat issue? (You actually don't have this problem in your main Wikipedia Miner service right now.)
Fixed by modifying Connectors in conf/server.xml.
http://blogs.sun.com/shankar/entry/how_to_handle_utf_8

You have to add:
URIEncoding="UTF-8"
to your Connectors when you experience such an issue.

It should look like this:
<Connector port="8080" redirectPort="8443" URIEncoding="UTF-8"/>