Yep. I'm trilingual English/French/Bulgarian, and i have all three as languages in Google search, and they're mixed up too often. I can understand Google proposing the French spelling of an English word and results for it, but almost every time when i search something in Bulgarian i get results in Russian, even when i use words that don't exist in Russian. The languages aren't even that close, and they aren't the only Cyrillic ones...
Well, those are quite close to each other from the orthographic point of view, I guess: Ukrainian or Serbian are visually very distinct from either Russian or Bulgarian, while to tell the latter two apart you need some actual knowledge about the differences of those languages: say, that the abundance of letter "ъ", words ending in "ът"/"та"/"то" and tons of prepositions (i.e., often repeated two-three letter words) are a pretty good indication of a Bulgarian text.
Yeah, it's annoying, especially since I've told Google explicitly the languages I know.
I do suppose that a lot of people haven't set their languages, and the automatic detection works well enough, most of the time.
