It takes time to get into the admin area of a site and do further testing. We always want to make sure we block off enough time to really do that investigation. I was just able to do that
Ultimately, the sh404SEF plugin isn't making a difference. If I go to an article, like loisir/jeux-video/un-jeu-video-pour-sauver-les-enfants-soldats-en-somalie and hit the refresh button in the browser, I'm seeing the button on almost every page load. There are some times, maybe 1 in 10 reloads, where the button isn't showing, and I'm unsure why that's happening.
If you go to the page right now, do you see the button at all? The sh404SEF plugins are disabled. Would like to hear your results.
Thanks,
Alex