404 when more than 1 filter

I’m trying to add 4 filters to a cpt with beutiful taxonomy filters. Filters display ok and when i choose one it works perfectly.
When i use more than one filter i receive 404 error

works 🙂
http://local.vodu.it/_WORDPRESS_/montasio/ricette/

works 🙂
http://local.vodu.it/_WORDPRESS_/montasio/ricette/tipo_montasio/mezzano/

404 🙁
http://local.vodu.it/_WORDPRESS_/montasio/ricette/tipo_montasio/mezzano/difficolta/media/

all 4 taxonomies are similar setup like that:
http://montasio.com/taxonomies.png

and cpt setup:
http://montasio.com/cpt.png

What’s wrong? I’m sure it’s due to permalink problems, it doesnt recognize the archive with more than 2 slashes

Thank you!