Index: /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22746)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22747)
@@ -1383,9 +1383,8 @@
 {
     unsigned cErrors = 0;
+    Assert(pPage->iFirstPresent != ~0);
 #ifdef VBOX_STRICT
     for (unsigned i = 0; i < pPage->iFirstPresent; i++)
-    {
-        Assert(!pShwPT->a[i].n.u1Present);
-    }
+        AssertMsg(!pShwPT->a[i].n.u1Present, ("Unexpected PTE: idx=%d %RX64 (first=%d)\n", i, pShwPT->a[i].u,  pPage->iFirstPresent));
 #endif
     for (unsigned i = pPage->iFirstPresent; i < RT_ELEMENTS(pShwPT->a); i++)
@@ -1445,9 +1444,8 @@
     unsigned cChanged = 0;
 
+    Assert(pPage->iFirstPresent != ~0);
 #ifdef VBOX_STRICT
     for (unsigned i = 0; i < pPage->iFirstPresent; i++)
-    {
-        Assert(!pShwPT->a[i].n.u1Present);
-    }
+        AssertMsg(!pShwPT->a[i].n.u1Present, ("Unexpected PTE: idx=%d %RX64 (first=%d)\n", i, pShwPT->a[i].u,  pPage->iFirstPresent));
 #endif
     for (unsigned i = pPage->iFirstPresent; i < RT_ELEMENTS(pShwPT->a); i++)