Are you able to provide which version of LaunchBox you are on, which theme you are using in Big Box, the version of the theme, where you got the theme, and which Video Playback engine you are using in Big Box (under System Menu > Options > Videos). Also, are you running anything in Big Box when it happens, Attract Mode or Screensavers. Is there a particular section in Big Box you are leaving it in when this happens. Does your computer go to sleep or monitors turning off after a certain time, or are there any power options that you have that turns off pieces of your computer, like USB ports, network, hard drives, things like that?