[support] Front page with i18n sometimes not working

Hello, on the site http://plats.polnetwork.biz I use i18n, so i have http://plats.polnetwork.biz/ca and http://plats.polnetwork.biz/es The front page is /inici on both cases, and the default language is /ca but from some machines the front (inici) is not working and appears an error "The required page could not be found" Any idea? Thank's for all Pol