Index: Modules/mmapmodule.c
===================================================================
--- Modules/mmapmodule.c	(revision 77420)
+++ Modules/mmapmodule.c	(working copy)
@@ -110,8 +110,10 @@
 mmap_object_dealloc(mmap_object *m_obj)
 {
 #ifdef MS_WINDOWS
-	if (m_obj->data != NULL)
+	if (m_obj->data != NULL) {
+		FlushViewOfFile (m_obj->data, m_obj->size);
 		UnmapViewOfFile (m_obj->data);
+	}
 	if (m_obj->map_handle != NULL)
 		CloseHandle (m_obj->map_handle);
 	if (m_obj->file_handle != INVALID_HANDLE_VALUE)
@@ -144,6 +146,7 @@
 	   TODO - should we check for errors in the close operations???
 	*/
 	if (self->data != NULL) {
+		FlushViewOfFile (self->data, self->size);
 		UnmapViewOfFile(self->data);
 		self->data = NULL;
 	}
@@ -162,6 +165,7 @@
 		(void) close(self->fd);
 	self->fd = -1;
 	if (self->data != NULL) {
+		msync(self->data, self->size, MS_SYNC);
 		munmap(self->data, self->size);
 		self->data = NULL;
 	}