Can you attach a test-file?

The chinese text I can easily test come from Project Gutenberg and are encoded in UTF-8. They work just fine, as far as I can tell (as I can't read the symbols and can only compare them one-by-one with a reference rendering).

Have you tried altering the encoding for that particular book? Do that by opening it, and selecting "change encoding" from the app-menu in the top-left.

Thanks!