I did not upgrade. As I have stated, it was a clean install.
After having the issue, I completely uninstalled, including database, and did it once again, following the installation guide you offer here: PhotoPost PHP Photo Sharing Photo Gallery Installation Guide
Mind you: This is the installation guide you link to from the customer area, where I download the product. To save yourself and your customers future trouble, it may be a good idea to update that with the installation routine that applies to the current version. I honestly do not expect to read the official installation guide onsite and then have to guess that there might be a different one in the package.