This morning I did a site command (just to check if I had joined the supplemental issue club) and found out that for some reason Google believes one of the pages is written in Japanese.

Mixed up Translate this page feature in Google

Though the issue is nothing new (I've seen it bouncing on and off occasionally), I can only wonder how hard it is for search engines to read the code and trust what it says:

<head xml:lang="fi" lang="fi">
...
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

Two very clear statements saying this page is written using a western character set language, Finnish to be more precise. So how come Google thinks this specific page is written in Japanese? I know our website has some quality backlinks from Japanese sites, so most likely this is a side affect from that. But why only this specific page shows "Translate this page" feature (to my knowledge it has zero japanese backlinks)?

So if you happen to be Google engineer reading this, please place this on your to-do list. Google expects webmasters to trust their guidelines, IMO it is only fair for Google to do the same and trust even a little piece of what website owners say about their site's origin.