I have a number of discounts and one of them is not acting as it is configured on my Drupal 6.22 MySQL database 5.1.52 and PHP 5.3.2, Ubercart 6.x-2.4 and Ubercart Discounts (Alternative) 6.x-2.4
The bug involves a role based discount with a minimum amount. If users are logged in, all is well.
However, if one is not logged in, this role based discount shows up when the minimum amount is reached. (Since it is a 40% discount, this is not a good thing.)
I deleted the discount and created an order not logged in, no sign of any discount.
Then I copied a discount that was working fine, changed the name and discount amount and role and saved it with the same name as the discounted discount.
The problem returned.
I deleted the new discount and created one from scratch, and the same problem occurred.
So I installed Cache Exclude and disabled cache on the admin/* and cart/* hoping that would help. It did not.
I have attached an export of the us_discounts table so you can see the configuration.