After include google font UBUNTU (not Condensed, not Mono) i discovered some issue.

In CHROME browser it does not show letter 'š' like 'škola' (school in slovak language). It show only '8' as upper-index. It is not problem with implementing, because it does not work on www.google.com/fonts too. You can try it yourself by choosing 'ubuntu' font in search box and typing (copy/paste) the word from my post into 'prewiev text'. In other browsers it works with no problems. Condensed and Mono as well...

EDIT:

i looks like conflict with local UBUNTU font.