Translation/language problem

I have successfully installed wordpress and established multisites (i want to do one page in slovenian and one in russian). Also i did the localisation, installed all the needed languages and everything.

The problem i have is that the main language of the theme i am using (benevolence by wplook) was set as english (US) and even though wp recognises the other two languages (in settings>general), when i choose them, they won’t be saved and the theme won’t translate. Settings say, that my choice was saved, but it just goes right back to english (US).

Also i already contacted wplook’s support, but they said it’s a bug that they’ve never seen before and it’s not theme related and it must be the installation.

Any ideas of where to look or possible solutions or workarounds…?

Thank you!