WordPress register_nav_menu suddenly stopped working locally

Ok, this is a biggie. Here's the deal:

I have upwards of 50 installs of WordPress running on MAMP Pro locally. For some of them I use local/whatever, for others I set up virtual hosts as whatever.local/. WordPress has never had any problems. Yesterday, installed a copy of WP 3.0.1 (fresh, straight off the server), and started templating. Today, I returned to it to continue, first by registing default navigations. I put the necessary lines in functions.php:

add_theme_support( 'menus' );

add_action('init', 'register_custom_menu');

    function register_custom_menus() {
        register_nav_menu('primary_menu', __('Header Menu'));
        register_nav_menu('404_menu', __('404 Menu'));
    }

Fine, right? I also tried it with register_custom_menu, one at a time. In WordPress, no default menus show up. I've tried:

• Activate a different theme, re-activate the original
• Try Twenty Ten - still no custom navigations although a 'primary menu' is registered in the code, so it is NOT my functions.php
• Tried another theme that I have running locally (that works perfectly in its original place), still no navs
• Delete the entire database and re-install WP
• Delete the entire directory, re-download WP, re开发者_开发百科install
• Delete the virtual host and work from localhost/whatever

So, I have a ton of other WP sites working perfectly fine with nav registering, but I can't create any more? I'm completely, totally lost.

Any input would be appreciated, right now I'm at my wit's end. Let me know if you need any more information.

Three things:

1. You should be hooking menu registration onto 'after_setup_theme', not 'init'
2. You don't need to call add_theme_support() since register_nav_menu() takes care of that.
3. You can use register_nav_menus() to take care of all your menus at once.

However, the biggest reason this isn't working is because you're not calling your function. The callback on add_action should be 'register_custom_menus' (notice plural). The spelling has to match the function declaration. This is how I'd suggest you rewrite it:

add_action('after_setup_theme', 'register_custom_menus');

function register_custom_menus() {
    register_nav_menus( array(
        'primary_menu' => __('Header Menu'),
        '404_menu' => __('404 Menu') ) );
}