Hi Chouby, Hi Joachim!
The development of Polylang is really impressive! In my production website (WP v.3.3.1), I still use the 0.7 version, as 0.7.1 didn't work.
I have activated a very useful plugin - Content Aware Sidebars - it enables to create sidebars for specific pages/posts, which will replace or be merged with the standard sidebars (primary, secondary, 4 footer sidebars).
The problem is, the Sidebars are a type of Post, which makes Language choice to show up in Sidebar Edit screen. But Polylang enables assigning languages to the Widgets already.
When I have ignored the language (left default) for all Sidebars, and added widgets for all 3 languages, every page in my default language was showing all the sidebar widgets in this language.
A workaround is to set a different language (unused in the website) for the Sidebars. I'm not sure, whether Content Aware Sidebars or Polylang could be modified to improve the compatibility, but I hope these infos could be useful for you.
Edit - WP version, link to C.A.S. plugin