Charles and branka I was getting the same thing you are. I made the thumbnail and the JPG and the wallpaper wasn’t showing up. I went to some completely different website (google for instance) and then I cleard all my cookies and browsing history and reloaded the site I was trying to see the wallpaper on, and it worked. I did it twice with two pics and had the do the same thing both times so it should work. I had to tell everyone who goes to my site to do the same thing. Go to a completely different site, delete all their browser history and cookies and other stuff and come back to your site and it should work. But it should work fine for people who haven’t been to your site yet and/or after you let everyone know to clear their cache and stuff before they come to your site to see your new wall papers:) There is probably a much much easier way to do it but I haven’t seen anything yet so I’m going to keep checking back for the real answer. But for now this is a band-aid that got me going and I hope it works for you:)

Also, lovely site. Stumbled across it via a link on the w3 css3 list. A good piece of serendipity.