Index: /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22741)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 22742)
@@ -2524,4 +2524,7 @@
 
                 default:
+#ifdef PGMPOOL_WITH_OPTIMIZED_DIRTY_PT
+                    Assert(!pPage->fDirty);
+#endif
                     Assert(!pPage->cModifications || ++cModifiedPages);
                     Assert(pPage->iModifiedNext == NIL_PGMPOOL_IDX || pPage->cModifications);