I've been messing with this problem for a while now, and it seems like there isn't much documentation, or people who have asked about this before. I've been trying to change the back640x480.jpg, back800x600.jpg,and welcome.jpg file in isolinux, but when I make the iso and boot it, none of the pictures show up. its just black instead of the modified images.
I also change them in the bootlogo CPIO archive, and then recompress it.
How can I make these image show?