Wouldn't just deleting the folders off the card do the same thing. I am getting a new camera tomorrow
and will have to use my card out off my 350D until the new one arrives next week. The folder out of my 350D is 370 on caculations thats 37,000 images. I don't want to start with that Number in my new camera. I will if I have to do the above but would have thought just deleting that folder would do the same.