It appears that the API isn't performing redirects that involve conversion of certain simplified Chinese page titles to traditional, but these redirects _are_ supported by the wiki's frontend.  For example:

When I enter http://zh.wikipedia.org/wiki/龙门飞甲 into my browser, this redirects automatically to http://zh.wikipedia.org/wiki/???T?w甲.

But when I do the equivalent query through the api with redirects enabled (http://zh.wikipedia.org/w/api.php?action=query&titles=龙门飞甲&redirects), I get no results.

Other simplified to traditional redirects do work in both the frontend and the API.  For example both http://zh.wikipedia.org/wiki/中国and http://zh.wikipedia.org/wiki/中?? lead to the same page.  I do notice that here, unlike in my previous example, the request for the simplified title shows on the page that the results are a redirect (（重定向自中国）), so something different must be going on.

Does anyone know what's going on here, or is there another Chinese language forum I should address this question to?

Many thanks,