One of our carts has a call center that handles phone orders 24/7. The operators purchase in CS-Cart just like a customer. For each customer, they use the Checkout As Guest function. But, CS-Cart is retaining the information from the previous caller. I verified that this happens with 2.0.15.
Example:
John Smith calls, and the operator adds his items to the cart and successfully places his order. Next, Jane Doe calls, the operator adds her items to the cart, goes to check out, and John Smith’s name, address, and shipping method are still in the cart.
I’m sure this is a cookie issue, but I don’t want to make any code changes that might affect regular customers. Suggestions?
Since these orders are being placed from the same machine, that machine has a session that is active and has the previous customer information stored. One way you could fix this is by clearing those session variables on the page that is shown after the order is placed (or probably better, in the controller php file for that page).
An even easier way is just to create the orders in admin instead of storefront. 
@ Grayloon. I am trying to do the same thing and it does work through admin but is much slower. I would be a happy bot if you can find the solution to this through the store front
I also have the quote/invoicing addon from www.snorocket.com which works almost just rght ( a little tweaking to do I belive)
John
Might try something like this…
Add a “top link” of dispatch=my_changes.clear
In the file addons/my_changes/controllers/admin/my_changes.php
add code similar to:
switch($mode) {
case 'clear':
unset($_SESSION['auth', $_SESSION['cart'])
return array(CONTROLLER_STATUS_OK, $index_script);
default:
fn_set_notification('E', $controller, "No such mode '$mode'");
retrun array(CONTROLLER_STATUS_NO_PAGE);
}
Good suggestion. I might give this a try.