--- a/windowing/windowserver/nga/SERVER/POINTER.CPP	Tue Apr 20 16:38:10 2010 +0100
+++ b/windowing/windowserver/nga/SERVER/POINTER.CPP	Fri Apr 23 14:57:14 2010 +0100
@@ -81,7 +81,9 @@
 	iEmulatorRotatePointerCoords = WsIniFile->FindVar(KWSERVIniFileVarEmulatorRotPointCoords);
 #endif
 
-	iRootWindow = CWsTop::Screen()->RootWindow();
+	const CScreen* screen = CWsTop::Screen();
+	WS_ASSERT_ALWAYS(screen, EWsPanicNoScreen);
+	iRootWindow = screen->RootWindow();
 	
 	TMachineInfoV1Buf machineInfo;
 	UserHal::MachineInfo(machineInfo);