--- ./nx-X11/programs/Xserver/xfixes/cursor.c.X.original	2015-02-13 14:03:44.792440567 +0100
+++ ./nx-X11/programs/Xserver/xfixes/cursor.c	2015-02-10 19:13:13.508696968 +0100
@@ -96,7 +96,8 @@
 	CursorCurrent = pCursor;
 	for (e = cursorEvents; e; e = e->next)
 	{
-	    if (e->eventMask & XFixesDisplayCursorNotifyMask)
+	    if ((e->eventMask & XFixesDisplayCursorNotifyMask) &&
+		!e->pClient->clientGone)
 	    {
 		xXFixesCursorNotifyEvent	ev;
 		ev.type = XFixesEventBase + XFixesCursorNotify;
