diff -ruN xserver-old/composite/compwindow.c xserver/composite/compwindow.c
--- xserver-old/composite/compwindow.c	2006-06-27 12:50:11.000000000 +1000
+++ xserver/composite/compwindow.c	2006-06-27 13:07:36.000000000 +1000
@@ -597,7 +597,8 @@
 	CompSubwindowsPtr	csw = GetCompSubwindows (pWin->parent);
         CompClientWindowPtr	ccw;
 
-	(*pScreen->SetWindowPixmap) (pWin, (*pScreen->GetWindowPixmap) (pWin->parent));
+	if ( pScreen->SetWindowPixmap && pScreen->GetWindowPixmap )
+	    (*pScreen->SetWindowPixmap) (pWin, (*pScreen->GetWindowPixmap) (pWin->parent));
 	if (csw)
 	    for (ccw = csw->clients; ccw; ccw = ccw->next)
 		compRedirectWindow (clients[CLIENT_ID(ccw->id)],