On my albums, where I have portfolio pricing, if you look at a single picture and click on the shopping cart button, you get the portfolio pricing for that photo:

If, however, you click the Buy button in the upper right hand corner when looking at thumbnails, the pricing that is provided for all the pictures, seems to be the default SmugMug pricing (starting at $0.38):

Needless to say, this is not desirable. It allows users to purchase my photos at a significant and unintended discount.
How do I fix this?