The menu items on your website change when I select either italian or english via the language flags. English: Home, Company, processing, Products... en in italian: Home, Azienda, Lavorazione, Prodotti... So the menu-items seem to be ok. For the articles I get different pages, either empty, in italian or in english. There is something strange going on there.
Can you check JoomFish' State? And give a screenshot of it?
Backend > Components > JoomFish > Control Panel > tab: State
Also, you seem to be using SEF, is this Joomla's SEF or a third party SEF component?
Can you give the rest of your System Details?
Backend > Help > System Info > System Info
- Database Version: e.g. 5.1.33
- PHP Version: e.g 5.2.9
- Web Server an version: e.g Apache/2.2.11 or ISS
- Web Server Operating System: Windows (e.g. the (Win32) in the web server info
- Web Server to PHP interface: apache2handler
- Joomla! Version: Joomla! 1.5.26 --> make sure this is the latest version: http://www.joomla.org/download.html
- User Agent: Mozilla/5.0 (Windows) - the browser and the operating system of the user
But first: update Joomla to the latest version!