Hi dms and welcome to the Q&A Board!
Not familiar with the Digital Picture Frame, but I did check out Phillips' website. It says:
As to the transferring problems, not sure what's happening. What method are you using to transfer them; software? click and drag? How many images are on the PC? Have you renamed some of the images and, if so, are they the ones that are not transferring? How did you create the slide show and in what format is it saved? Is the slideshow stand alone, or does it require transfer of the images?
I'm also wondering if part of the problem is that whatever changes your made to the images are not compatible with the card formatted by the camera.
Before doing any additional formating of the cards, check your manuals or call the manufacturers for help. Incorrect formatting can ruin a card, and one gig cards are not cheap to replace.