there is an issue on the update, I think is fixed but it is not fully tested here is a link the version that has a few quick fixes. Image store 3.1.5 RC!
Yes it still does it for both image sizes and print finishes. Its not in the price list itself but rather its under the image sizes and print finishes to create new items to add to the list.
After more testing it looks like i can now add more print finishes, shipping, color options and color filters but im still having a problem adding more than 6 image sizes.