OK, I see the problem (not the solution :), and working on it...

OK the actual problem is this: the php.net pages are cached on several proxy servers and public caches. Every non-manual page (all pages where the language cannot be set explicitly from the request) uses the accept-language header, the mirror's default language or the "en" language in this priority order.

As we had no dynamic language detection before, this was not a problem. But now accept-language can be different for users (well, this is the whole point of that). So pages go out to caches with the language code used by the "first" guy who have downloaded the page, and you get that page from the cache. This is a problem on all non-manual pages.

On manual pages, the language used in the form is always the  language of the manual you see, so there is no problem there.

I think the solution will be to not pass the language in the search form on non-manual pages, as it can be extracted from the environment without that value (your accept-language is not changed between filling and submitting the form).

I'll look into this today a bit later...

OK, I have removed the langauge parameter from the search form. Now it only appears in case it was explicitly specified in the request (via a documentation URL or search query). So your problem should be fixed. Please repoen this bug, if you feel otherwise.

Thanks. I am now getting results in english.