symfony2 CSRF invalid
Are you by chance using $form->bindRequest() in the action which produces the CSRF error? I had this issue. You should not be binding the request for a new form. If you are posting the form to the same action, wrap the bindRequest in a conditional which checks if method is POST:
if ($this->getRequest()->getMethod() == 'POST') { $form->bindRequest($this->getRequest()); if ($form->isValid()) { ... }}