Compatibility issue between tweetmeme and qtranslate

I’m having a compatibility issue between tweetmeme button and qtranslate. I’m managing a bilingual blog at https://brunosbille.com.
If I go to the latest post (https://brunosbille.com/?p=864), by default it’s in French and if I click the tweetmeme button, I get a shortened URL redirecting to the right URL of my post (https://brunosbille.com/?p=864). Now if I switch to the English version, the URL of my post is now https://brunosbille.com/?p=864&lang=en but the shortened URL is https://brunosbille.com/?p=864&lang=en. So when I click the link from the tweet, I get to the French version of my post instead of the English one, because the lang=en parameter doesn’t seem to be taken into account. And it has a nasty side effect too: retweets are not properly counted.

In the plugin code, I noticed that the permalink of the code is urlencode’d. I tried to replace urlencode($url) by rawurlencode($url) but it didn’t change anything.

Does anyone have an idea how I can make this work?