On a freshly installed xwiki-enterprise-jetty-hsqldb-2.1-20091111.133728-212.zip
1. Log in as Admin.
2. Edit preference, Multi Lingual = "Yes". Languages = "en, zh". Default Language = "en"
3. Save preference.
4. Problem: There is only "en" display on the upper right page as shown in the screen shot.
And there is another problem in the register page http://192.168.1.103:8080/xwiki/bin/register/XWiki/Register. "default" is displayed in the place of "en" as in other pages. Clicking on it it will navigate to http://192.168.1.103:8080/xwiki/bin/view/XWiki/Register?language=default.