When I add wallpapers via the little "+" under "Appearance Look" in the settings, I can select them and it works fine. But when I reopen the Appearance setting and want to change my wallpaper, the custom ones are gone. Why is this? Below is a screenshot of the empty custom wallpaper section. Unfortunately I don't know what this is called in English, so I have a hard time searching for my problem. http://i.stack.imgur.com/eyytG.png