I'm going to need some more information to be able to tell what may be wrong.
forst, for testing purposes, create a new page and add the eCart Display Manager to it. In the display manager, go to the second page and set it to show all columns.
then add the following code just before the closing <html> tag:
<pre><?php var_dump($_SESSION); ?></pre>
now login as one of the users that is not working correctly and add something that should be discountable to the cart, then go to the test view cart page.
send a screen shoot of this page in a zip archive and a detailed explanation of how the discounts should be displaying versus how they are displaying.
it's to know what may be wrong with the info you have provided. I'm not entirely sure how they are supposed to be working, nor am i sure how they are working, I need that information to be able to investigate.
