Chouby on "Polylang and WordPress SEO by Yoast"

Yes. I confirm the conflict. It can be solved either in WPSEO or Polylang.

In polylang/admin/admin-filters-term.php at line 39, replace:

add_action('edit_term', array(&$this, 'save_term'), 10, 3);

by

add_action('edit_term', array(&$this, 'save_term'), 100, 3);