Page language determination

ignorato?

[bull]

Having translated a substantial part of a project into italian (besides the english and german version); I naturally watch google.it now, too. All pages are linked to each other to enable a quick language switch. And every page has declared its language as, e.g.

xml:lang="de" lang="de"

The recently translated italian version has not been yet indexed. Searching in google.it for kw1 kw2, the project shows up at #2, #3. Displaying all results from the project via site: does reveal all pages, and searching in these results those pages only in italian shows about 80% of these results. None of these pages is in italian.
This leads me to the conclusion that a language declaration on the page is ignored.
Note: The page title is italian in all language versions, as kw1 kw2 is italian and cannot be translated.