we have this:

if (g_file_is_native (parent->file) && dir->monitor == NULL) {
	dir->monitor = g_file_monitor_directory (parent->file, 
						 G_FILE_MONITOR_NONE,
						 NULL,
						 NULL);
	if (dir->monitor != NULL)
	{
		g_signal_connect (dir->monitor,
				  "changed",
				  G_CALLBACK (on_directory_monitor_event),
				  parent);
	}
}

If I do not comment this gedit crashes in windows.

the on_directory_monitor_event:

static void
on_directory_monitor_event (GFileMonitor * monitor,
			    GFile * file,
			    GFile * other_file,
			    GFileMonitorEvent event_type,
			    FileBrowserNode * parent)
{
	FileBrowserNode *node;
	FileBrowserNodeDir *dir = FILE_BROWSER_NODE_DIR (parent);

	switch (event_type) {
	case G_FILE_MONITOR_EVENT_DELETED:
		node = node_list_contains_file (dir->children, file);

		if (node != NULL) {
			model_remove_node (dir->model, node, NULL, TRUE);
		}
		break;
	case G_FILE_MONITOR_EVENT_CREATED:
		if (g_file_query_exists (file, NULL)) {
			model_add_node_from_file (dir->model, parent, file, NULL);
		}
		
		break;
	default:
		break;
	}
}

You can have a look at the code in:
http://svn.gnome.org/viewvc/gedit/trunk/plugins/filebrowser/gedit-file-browser-store.c?view=markup