Attributes Price Factor Not Showing on Cart

Thought I had this worked out right but it seems that the price factor does not show up on cart!

I have a product set up as follows:

Product priced by attributes - NO
Under Attributes controller:
Price - 0.00
Price factor - -0.50 ( for less 50%)
Price offset - 0.00
Include base price when priced by attributes - NO

On the product page it shows that the particular attribute has a 50% off price however when I select that attribute and add to cart the price remains at the base price.

What am I doing wrong?

URL to the site please?

oops, sorry www.makemytable.com

Go to the table napkins 20x20, there are several swatches there with discounted price. the discount shows up on the swatch but as you add it to cart, the discount is not applied..

limelites:

URL to the site please?

I managed to answer my own question although in the book, it specifically says that priced by attributes should be set to NO.

It seems that if the price is directly deducted, then this works but if you are working on percentages, then the product priced by attributes should be set to YES for this to work.