I've been using the same cards, same camera and same program (PSE7). Today, after working with some photos, when I put them in the digital picture frame, they came up as "INVALID" and would not display. The only other time I had that was when the files were too big. I resize everything to 800 on the long side. They are all jpg as I thought maybe I saved them in some PS format. They do show up just fine on the computer. Any suggestions?