Okay, I think we're in a bit of a sticky problem here:
turns out the live search will only work with languages installed in the respective language folder - for example, it will work with Russian if you have the ru_RU folder in the theme/language. Also, it will only work, if the corresponding language is selected in the Post an ad dialog during creation - otherwise it won't be found - beats me why!
More seriously, it will not find any listings, both live and normal search if the listing isn't in the current interface language. For example, if I'm in Russian and type search term in English - no listings are found, even if they exist. That is quite a problem, as even if the interface is in foreign language, you'd still be searching for iPhone or PlayStation typing it in English, right? Currently, you need to switch to English interface to be able to do that, which no one visiting your site would even think of doing in order to get search results.
So, the question is, how can we fix this, as it is just unusable in it's current state?
EDIT: Seem to be a core problem, damn
Search only looks into ads, that the seller created while using the same language settings as your current ones - totally defeats the idea of having multi language site - if you want to filter by language, there should be filter for it, not filter by current selected interface language. Anyone that has a workaround?