Are you running any firewall software, such as Symantec Internet Security? It may be programmed to automatically block images with certain letters, such as "banner" or "ad". Or, it may block any images from certain sites that it thinks is advertising: GeoCities, Angelfire, etc. If you see a globe icon in the taskbar, then you're probably running the Symantec program. Right-click and select "Disable", then reload the Renderosity page.