[Plugin: Qtranslate Slug] Link in English give French language !!!

Hi,
I’ve found another problem there:
My Qtranslate contain 2 languages: french (the first) and English.
I’m using “postname” as permalink in wordpress and /fr /en in qtranslate.
When i try to share one of my post in english with the right link, on facebook or google+, the excerpt on the wall is in French!!
If I create a new post, the share is in english, but all the old posts doesn’t work. After some days, the new posts created show also the excerpt in French. Does it comes from old slug in wordpress??
Anyone knows this issue??
Thanks
Stéphane

https://www.ads-software.com/extend/plugins/qtranslate-slug/