Hello Ryan, yes it's exact !
I want to store an array because I've several search engines on my home page. it's easy to retrieve datas (sanitized) from an engine by stocking an array in session.
$session->engine1datas, $session->engine2datas, $session->engine3datas, where engine1datas, engine2datas, engine3datas are arrays.
For example, I'm doing like that : $session->set("engine1datas",$input->post);
But it doesn't work only when I try to read session on the home page, that's strange...