Index: /trunk/src/VBox/VMM/PGMSharedPage.cpp
===================================================================
--- /trunk/src/VBox/VMM/PGMSharedPage.cpp	(revision 29602)
+++ /trunk/src/VBox/VMM/PGMSharedPage.cpp	(revision 29603)
@@ -136,4 +136,8 @@
 static DECLCALLBACK(VBOXSTRICTRC) pgmR3SharedModuleRegRendezvous(PVM pVM, PVMCPU pVCpu, void *pvUser)
 {
+    /* Flush all pending handy page operations before changing any shared page assignments. */
+    int rc = PGMR3PhysAllocateHandyPages(pVM);
+    AssertRC(rc);
+
     return GMMR3CheckSharedModules(pVM);
 }