Images are being resized!!

For some reason, just two of my products (as of right now) are resizing the featured image.
http://bigfishdigital.net/syntech-lubrication/gasoline/
As you can see on this page, two of the products are not aligned. Even though all images are the same size when uploaded, two of them are somehow getting resized to 124px × 140px. How can this be fixed?
Thank you!

http://wordpress.org/plugins/grid-products/