Index: /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 27464)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllPool.cpp	(revision 27465)
@@ -1536,4 +1536,8 @@
     pPage->fDirty = false;
 
+#ifdef VBOX_WITH_2X_4GB_ADDR_SPACE_IN_R0
+    uint32_t iPrevSubset = PGMDynMapPushAutoSubset(VMMGetCpu(pVM));
+#endif
+
 #ifdef VBOX_STRICT
     uint64_t fFlags = 0;
@@ -1581,4 +1585,8 @@
     else
         Log(("Removed dirty page %RGp cMods=%d cChanges=%d\n", pPage->GCPhys, pPage->cModifications, cChanges));
+
+#ifdef VBOX_WITH_2X_4GB_ADDR_SPACE_IN_R0
+    PGMDynMapPopAutoSubset(VMMGetCpu(pVM), iPrevSubset);
+#endif
 }