"fields" does not respect language

[rnervi]

I need to "attach" some pdf to product in a 2 language site.
Thus created "fields" (and fields group) per language.
Then in two article mode (for 2 languages) putted two differnt (by lang & Name) files.
In frontend, product detail, it shows both them (2 languages) in the middle tabbed place but the download is showed the right way

from frontend:
Descrizione
Allegati
Attachments <------ not of current language

poduct description

Scheda Tecnica <-- language fields prompt, correct
XXXX_Italiano.pdf