Disappearing Firefox Window

[geoffrey]

I have noticed that while watching Youtube or Googlevideo videos with LMCE (using the "Computing" from the "Advanced" menu)  that the Window will disappear after 5-7 minutes.  The videos sound will still be present but I am left with nothing other than the flickr image and the two buttons in the bottom corners of the screen.  anyone know how to prevent this?

[golgoj4]

http://wiki.linuxmce.org/index.php/Screen_saver_timeout