Default language keeps popping up

[ Moderator note: Title changed to something more appropriate. Please review the Forum Welcome and try to follow the rules. ]

When I go into any language in the site, the language appears, but when I go to another sections then it changes to default language….

I checked many times, reinstall, goes to previous version of wordpress etc etc
PLEASEEEE could someone HELP ME!!??

BTW the language for the settings in the panel control is Italian and I can not change it either…..

THANKS SO MUCH!!!!!

http://wordpress.org/extend/plugins/qtranslate/