Discount for Product Price Not Applied

Hello,
My situation is, when a customer adds a quantity of four or more to a product, I want to set a discount of $40 off the price of that product. I have setup up a discount conditions and actions to do this (see discount1.JPG attachment) but whenever I add that product and change the quantity to four it never adds the discount onto it. Also whenever I add a product to the shopping cart, no matter if I have set up a discount for it or not, the shopping cart gives me this error, "warning: Invalid argument supplied for foreach() in /home/inst5969/public_html/modules/uc_discounts/uc_discounts.module on line 309." (see discount2.jpg attachment).

Any help would be greatly appreciated!
Thanks in advance.
Stephen