Problems with ACL

I have two controllers: each of theses have an AJAX action. In the ACL, I don't allow access to anyone of these actions.

For the first action, this works, but for the second no. Their code is like:

$this->view->disable();

$request = $this->request;

if($request->isPost() === true)
{
    // Create a response, set it, return it.
}

And in the second action $request->isPost() is false. I just have skipped something?