Hi, I have a product (not priced by attributes) that has a base price of $20. I have an attribute with several values, each of which should reduce the base price by a certain factor.
Here's what I have set for one of them:
Click image for larger version.  Name: pricefactor.jpg  Views: 204  Size: 9.0 KB  ID: 5737

The attributes controller shows the expected price reductions properly:
Click image for larger version.  Name: attribctrlr.png  Views: 226  Size: 10.0 KB  ID: 5738

as does the selector on the product page:
Click image for larger version.  Name: productattrib.png  Views: 222  Size: 4.3 KB  ID: 5741


the problem is that after I have added the product to the cart, the price reduction is not shown. The expected total is $10.
Click image for larger version.  Name: cart.jpg  Views: 197  Size: 8.9 KB  ID: 5743

If I change the factor so that it is no longer negative (I changed -0.5 to 0.5), it adds it in as would be expected. With the positive factor, the price shown in the cart was $30.

Is this a bug in zen cart? Or am I doing something wrong?