Screen saver activates? Do you mean that it turns off your screen? When we refer to the screen saver, we are refering to the panning and zooming of random photos from your library or Flickr, which is completely different from when the Orbiter shuts down AV equipment after a timeout.. which are you referring to? The Photo Screen Saver will never interrupt anything you are doing, that is just something that happens in the background.
However, shutting down AV equipment after a timeout is normal. If LMCE decides that no media is playing or activity is happening, that is what happens. If you are going to the KDE desktop to do web browsing then this is quiet possible as LMCE doesn't see activity in the desktop. If this is the issue, you should be browsing from the Computing menu as this means LMCE can see the activity, then it won't shut down.