Index: /trunk/src/VBox/NetworkServices/NAT/pxping.c
===================================================================
--- /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 49864)
+++ /trunk/src/VBox/NetworkServices/NAT/pxping.c	(revision 49865)
@@ -530,6 +530,6 @@
         IPH_OFFSET_SET(iph, ntohs(IPH_OFFSET(iph)));
         IPH_LEN_SET(iph, ntohs(IPH_LEN(iph)));
-        /* wants checksum */
-        sum = inet_chksum_pbuf(p); /* sic(?) */
+        /* wants checksum of everything (sic!), in host order */
+        sum = inet_chksum_pbuf(p);
         IPH_CHKSUM_SET(iph, sum);
 #else /* !RT_OS_DARWIN  */