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