That's exactly what I'm doing: taking the working .desktop file, editing it exactly as instructed, making sure the path is exactly right, loading it to n900 via USB into the .images file, and disconnecting (Otherwise you can't do much at all on n900).

Then I go to 'change background' and I see 'Image set - Bubbles' but the thumbnail beside is it blank. It's not finding the images. If I choose it, nothing happens as the images aren't found.

Now, I don't know what I'm doing that is different from what you're doing - cos if I knew that, I'd do it right, yes? I've pasted the path I'm using higher up the trhead, and no-one could tell me why it doesn't work. I know I'm stupid but it doesn't help just telling me that!