Issue's solve, thanks to Carlos from qv support.
The problem was that i've edited the QvAjax.js like explained in this thread http://community.qlik.com/message/58458#58458.
Next, i've updating the qv server from SR1 to SR2 and it look QvAjax.js wasn't replace by the installer. I think it was conflict in QvAjaxZfc files.
--> I've restore the QvAjax.js from SR1 backup file and its works