Index: /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22710)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22711)
@@ -1618,4 +1618,5 @@
 {
     PPGMPOOL pPool = pVM->pgm.s.CTX_SUFF(pPool);
+    Assert(PGMIsLocked(pVM));
     if (!pPool->cDirtyPages)
         return false;