Last modified: 2010-06-23 13:44:47 UTC
The API does not response all available translations for a certain article. For example: This is the answer of the API request: http://pl.wikipedia.org/w/api.php?action=query&titles=Muzeum_Azji_i_Pacyfiku&prop=langlinks&lllimit=max&format=xml But this article is available in other languages as you can see here: http://pl.wikipedia.org/wiki/Muzeum_Azji_i_Pacyfiku
That's because http://pl.wikipedia.org/wiki/Muzeum_Azji_i_Pacyfiku is a redirect to http://pl.wikipedia.org/wiki/Muzeum_Azji_i_Pacyfiku_w_Warszawie . Look at http://pl.wikipedia.org/w/api.php?action=query&titles=Muzeum_Azji_i_Pacyfiku&prop=langlinks&lllimit=max&format=xml&redirects and you'll see the result you wanted. The result you linked is correct, because there are no langlinks on the redirect page.
Oh, sorry. I did not know that feature.