how to only show certain pages in nav menu?

Hi, I am building a site that needs quite a few different pages, so I need to exclude (or include) certain pages in the nav menu.

First I tried the “exclude pages” plugin, which seems to work, except that now I get 2 different menus that show up for users, 1 is the correct one and only shows the pages I want it to. This only works in Safari when logged in. The other menu is a seeming random selection of pages, and displays for most other browsers and for logged out Safari users.

I also tried adding this code to header.php to no effect:

<?php wp_list_pages('include=108,134,7,9,13&title_li'); ?>

exclude code has no effect as well…

Any ideas?