I deleted the themes, deleted the files in Feeds en emptied the Enclosure folder. When I download the theme again and choose yes to download attached files, the file in Feeds gets created OK, the folder in Enclore is made but stays empty.
When I edit the theme file I find the link for the RSS feed with the images.
However when I open this I get an error 404, so it seems normal to me that images don't get downloaded because the themeserver is broken at the moment. Or is it just me who gets this 404 error? Thanks for your response.
PS: I you already got bing dynamic theme, the images show fine because you already have them. Try downloading another dynamic one, you hadn't tried before. They all stay black for me.