Tried getting custom backgrounds, now have nothing...

Hi all,

I tried using this (http://www.youtube.com/watch?v=uWvbaN-3q6I) to get custom backgrounds but it's failed. Whenever I turn the kindle off, there is no background at all. Does anyone know what happened?

I have a kindle 4, version 4.0.1. I did everything in the video.

I've got 800x600 pictures, I put them into the screensaver folder. Still nothing. Please help.