I'm having a very similar problem to the one mentioned in this post: http://en.forums.wordpress.com/topic/wordpress-beginner-please-help-disappearing-pages?replies=8
except the solution given mentioned there doesn't work for me.
My theme was working fine (I'm the process of building my site - www.tamsynbellydance.com), but I wanted my page menu to appear in two columns instead of one big one. After reading about the options for wp_page_menu() I installed the plugin "My Page Order" and applied it as a widget on my footer to create two menus, each one excluding half of my page IDs. However, with the exception of my home page link, doing this made all the page menu items disappear - clearly a very bad thing. Now if I go to 'pages', they all list still as public and published, and I can access them if I type in the URL directly, but nothing I do seems to bring back the menu. The CSS code in footer.php looks the same as it was. I tried getting rid of custom menus and adding them back. I tried changing templates and reloading my desired template, which was touted as a solution elsewhere, but nothing worked.
Any ideas? I'm stuck and could use some advice!
Thanks.