The issue has to do with your content on Revolution slider.
Looking at your site’s source code, I can see Layer Number 3 on the http://www.yahadinunum.org/wp-content/uploads/2014/05/Capture-d%E2%80%99e%CC%81cran-2014-09-22-a%CC%80-15.37.54.png image has a link tag that has not been closed. This is causing it to be duplicated throughout the page on some browsers.
The tag says <a href='javascript:alert("http://www.yahadinunum.org");' class='tp-button lightgrey small'>Search the Map
and either needs to have the </a>
added to the end or needs the <a href='javascript:alert("http://www.yahadinunum.org");' class='tp-button lightgrey small'>
portion removed.
I’m not familiar with Revolution Slider to know where exactly that can be fixed, but that is where you will want to look.