Index: /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h	(revision 20068)
+++ /trunk/src/VBox/VMM/VMMAll/PGMAllBth.h	(revision 20069)
@@ -818,5 +818,5 @@
                         uint64_t fPageShw;
                         rc = PGMShwGetPage(pVCpu, pvFault, &fPageShw, NULL);
-                        AssertMsg((RT_SUCCESS(rc) && (fPageShw & X86_PTE_RW)), ("rc=%Rrc fPageShw=%RX64\n", rc, fPageShw));
+                        AssertMsg((RT_SUCCESS(rc) && ((fPageShw & X86_PTE_RW) || pVM->cCPUs > 1 /* new monitor can be installed during trap e execution */)), ("rc=%Rrc fPageShw=%RX64\n", rc, fPageShw));
                         pgmUnlock(pVM);
 #   endif /* VBOX_STRICT */