@mikejin1,

We upgraded the plugin to support Firefox 3.6.* ages ago, so it should be compatible unless you're grabbing it off an outdated link somewhere. I've just tested locally on a Chinese version of Windows and everything seems to be working. If it doesn't work for you please just let us know your OS and whether you're installing the logged-in or logged-out version?

You may also want to confirm you're grabbing the plugin from this page, which builds it for you based on the latest sources:

http://popupchinese.com/chinese/plugin

Best,

--david