Index: /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h	(revision 20064)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h	(revision 20065)
@@ -1686,4 +1686,5 @@
     {
         AssertMsg(pVM->cCPUs > 1, ("%Unexpected missing PDE p=%llx\n", pPdeDst, (uint64_t)PdeDst.u));
+        Log(("CPU%d: SyncPage: Pde at %RGv changed behind our back!\n", GCPtrPage));
         return VINF_SUCCESS;    /* force the instruction to be executed again. */
     }