If clicking the boxes does not work, it normally means there’s a conflict with another plugin, as I was unable to see this on your site I can’t tell you what and where exactly, but I would suggest looking at the javascript error console, preferably in firebug.
Kama kubonyeza masanduku haifanyi kazi, ni kawaida ina maana kuna mgogoro na Plugin mwingine, kama nilikuwa hawawezi kuona hii kwenye tovuti yako siwezi kuwaambia nini na wapi hasa, lakini napenda kupendekeza kuangalia console kosa javascript, ikiwezekana katika Firebug.