diff -Nurp patched/Xi/exevents.c working/Xi/exevents.c
--- patched/Xi/exevents.c	2009-01-15 23:02:52.000000000 -0800
+++ working/Xi/exevents.c	2009-01-15 23:09:42.000000000 -0800
@@ -194,12 +194,15 @@ CopyKeyClass(DeviceIntPtr device, Device
     BOOL sendNotify = FALSE;
     int i;
 
-    if (device == master)
+    if (device == master || device == NULL || master == NULL)
         return;
 
     dk = device->key;
     mk = master->key;
 
+    if (dk == NULL || mk == NULL)
+        return;
+
     if (device != dixLookupPrivate(&master->devPrivates,
                                    CoreDevicePrivateKey)) {
         memcpy(mk->modifierMap, dk->modifierMap, MAP_LENGTH);