I don't know why it not working for you. For me no problem. Or do this: Copy your images to /home/user/MyDocs/backgrounds/ And run this on terminal as root: Code: cp -f /home/user/MyDocs/backgrounds/*.png /usr/share/themes/transparent/meegotouch/images/backgrounds/ Then refresh/reboot.
cp -f /home/user/MyDocs/backgrounds/*.png /usr/share/themes/transparent/meegotouch/images/backgrounds/