Index: /trunk/src/VBox/NetworkServices/NAT/pxping.c
===================================================================
--- /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 50020)
+++ /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 50021)
@@ -770,6 +770,6 @@
 {
     LWIP_ASSERT1(pxping->npcbs > 0);
-    LWIP_ASSERT1(pxping->next == NULL);
-    LWIP_ASSERT1(pxping->pprev_timeout == NULL);
+    LWIP_ASSERT1(pcb->next == NULL);
+    LWIP_ASSERT1(pcb->pprev_timeout == NULL);
 
     printf("%s: ping %p\n", __func__, (void *)pcb);