Index: OSGShadowViewport.cpp
===================================================================
RCS file: /cvsroot/opensg/OpenSG/Source/Experimental/ShadowViewport/OSGShadowViewport.cpp,v
retrieving revision 1.41
diff -u -r1.41 OSGShadowViewport.cpp
--- OSGShadowViewport.cpp	19 Jan 2011 16:22:01 -0000	1.41
+++ OSGShadowViewport.cpp	26 Aug 2011 05:51:31 -0000
@@ -1369,7 +1369,8 @@
         {
             if(i < _lightCamBeacons.size())
             {
-                getRoot()->subChild(_lightCamBeacons[i]);
+				if(getRoot()!=osg::NullFC)
+					getRoot()->subChild(_lightCamBeacons[i]);
                 subRefCP(_lightCamBeacons[i]);
             }
             if(i < _lightCameras.size())