[Plugin: LeagueManager] Problem with adding month

Great plugin,but I have problem adding new matches… Site is on cyrillic, and when I try to add new matches, select Month gives me this “funny” symbols instead of the real month – ‘Ñ�анÑ�аÑ�’

Here is the screenshot:
‘http://www.golobrdo.co.rs/hajduk/images/language-problem.jpg’

Does anyone know how to fix this?

http://ww.wp.xz.cn/extend/plugins/leaguemanager/