Mqtranslate and WordPress 3.9

I have a dual language blog, english and french, using Mqtranslate 2.6.2.4.
Since I upgraded WordPress to 3.9, adding a new post or page or newsletter gives me a single default language (en) title and the text area has no editing icons (except insert media). If I create a post then I get a dual language title (same title twice with en and fr indicators) and the text in the same way. The language change widget changes the site and existing contents ok.

I have the same blog with the same versions on my local pc and this set up works correctly! I’ve tried disabling all my plugins etc but still no luck. Any ideas of what to look for?