Reposting from: http://www.zen-cart.com/showthread.p...35#post1181435

This error can be reproduced on a new installation.

1. Create a product with price at $21.95
2. Install Table Rates shipping module with these settings:
Shipping Table - 25:7.99
Table Method - item
3. Create a coupon with a 10% reduction
4. Restrict the product in step one from using this coupon
5. Add this item to your cart - only this item
6. Select the table rates for shipping
7. Enter the coupon code from step 3
8. A yellow alert box appears "You must spend at least US$0.00 to redeem this coupon "

The alert should be "This coupon code is not valid for any product currently in your cart."

This problem only occurs in a very specific price range. If you have two of the items @ 21.95, the correct alert shows up.