Cache not reflecting url

Hi, Wether it be caches_page or caches_action, the cache isn't reflecting the url my routes are generating from e.g:

map.resources :infos, :path_prefix=>'/:lang', :name_prefix=>'lang_'   my url => /en/infos map.resources :infos, :path_prefix=>'/:lang/:archived', :name_prefix=>'archived_'   my url => /en/all/infos

but I only get /en/infos.html. (I've checked in dev mode, it works so nothing to do with wrongly passing params or something )

thanks for your help, I'm really getting to think there is a bug in the cache system

charly