I've created a custom MetaPicture and associated it as background image to a "Tiles Desktop" in V2CP5.04. I've also embedded the image file in the MetaPicture as explained in a KB article I found. When I open the properties of the MetaPicture I can see the image in the "Vizualization" tab, but on the web client, I only see a grey background. I also cleared the images cache. Is there anything I'm missing? Does the image file need to be placed in any specific folder?