Header image not displlayed

Hi, seams that there is an issus with the Header Image. I played with the settings, added new pictures and removed them. Now I can still select an Header Image in the Header section. The Image is displayed in the preview area. But in real life this Image is not displayed. The Header is black! When I logged-out an logged-in again there is no Header Image selected. This looks strange to me. Please help. http://sf-plochingen.schachvereine.de/sfp2