PowerStore: Image Upload, wrong format message

My client is receiving a message asking for the proper image format when trying to insert a new product into the site which is now on a live hosting server. They claim they have the images in the standard JPG format and in an easy to find location on their machine which should work, but they get the message about using a proper image format.

I can successfully add both information and images with no problem from three different machines (PCs and Macs).

I suspect there is something simple that the client isn't getting quite right, but I thought I'd post here and see if anyone else might have an idea where to look first.

I thought I saw something in one of the threads here about that but I can't find it now.

My client will be coming by later today and I'll work with their machine to see what the deal might be. I'll post here with an update to help with the knowledge base.

This is somewhat related to my earlier posts about inserting products in PowerStore (v. 1.x).