Ecart makes use of the session id for the internal id of the cart. If this value is not set then you will have issues with the checkout and the cart in general. If you make a php info page you should be able to see this value. An info page is any php page with this line of code in it:
<?php phpinfo(); ?>
When you view this page look for the this setting:
_REQUEST["PHPSESSID"]
or
_COOKIE["PHPSESSID"]
The session id should be available on the page anytime after session_start() is called. You can also generate a session id with the session_regenerate_id() function. You can add a check to see if the session id exists and if not start the session and generate a new id like this:
<?php if(!session_id()) session_start();
if(!session_id()) session_regenerate_id();?>
As for the order not being there what value do you see and what is the code that is referenced for this?