[Plugin: WP e-Commerce] Can't upload a file for product download

I can’t upload a file in the “Product Download” section. When hitting update/publish, I can see the form uploads the file, but then the box is empty.

The files I’m trying to upload are less than 5mb, and the max upload size indicated in that box is 7mb.

Anyone else having the same problem?

https://www.ads-software.com/extend/plugins/wp-e-commerce/