Try going to the admin panel http://www.kafly.com.br/cargo/admin, the admin panel doesn't use the same skin, so it should be ok, go to settings->genral settings and go to the select skin and select crystal, and save and hopefully it should be fixed. If not, uninstall, delete all the files and re-upload them and then install again, and hopefully it should be fine then.
Cheers
Dan C