I have never been able to make the download of digital images work. I have read the forums and Xpark responded to a contact email staeing checked system seems ok.
I have today created a new test price list with down checked and 660 by 660 px defined after that I uploaded two new 660 by 660 images to a test gallery and purchased them.
When I was logged in ( admin) i recieved a download link on the receipt page and receipt email to; http://vidpicpro.com/new/wp-content/plugins/image-store/admin/download.php?_wpnonce=e7fa0b0bb8&img=m6ampayf&sz=test2digital&c=

retested when logged of and link was:
http://vidpicpro.com/new/wp-content/plugins/image-store/admin/download.php?_wpnonce=b06d96413b&img=m6ampayf&sz=test2digital&c=

I presume different user and same image ids both links gave a blank screen

On the sales page both transactions payment conformed from paypal.

Wondering of my download.php is faulty??