You should attach the image you're using. Grub will fail to display the image correctly unless it's in the right .xpm format. ImageMagick can create the file for you.
convert -resize 640x480 -colors 14 picture.jpg ImageName.xpm -- GRUB splashes doesn't work in Dapper https://launchpad.net/bugs/51866 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs