Permalink /%category%/%postname%/ returns 404 on OSX

Question

I'm on OSX 10.8.4 with a pretty standard installation of Wordpress 3.6.1 under the local OSX Apache/MySQL.

If my permalinks are set to /%category%/%postname%/ I get a 404...

This is working on the live server which I think is running CentOS, so it's definitely something wrong on my machine.

I don't have any custom post types. I am using the wp-no-category-base plugin, but removing that has no effect on the 404 problem.

Same problem using default theme.

/%category%/%year%/%postname%/ works, as does /%category%/%post_id%/%postname%/, although:

/%category%/%postname%/%post_id%/ puts the ID on the end of the URL twice...

Check out the config details I've got:

My mod_rewrite is on in httpd.conf (LoadModule rewrite_module libexec/apache2/mod_rewrite.so)

My .htaccess looks to be properly generated by Wordpress:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

And my httpd-vhosts.conf has the correct AllowOverride All lines in it (check out the commented lines for other things I've tried!):

<VirtualHost *:80>
    ServerName sitename.gareth.dev
    DocumentRoot /Users/G/Sites/SiteName
    DirectoryIndex index.html index.php

    <Directory /Users/G/Sites/SiteName>

        Options Indexes FollowSymlinks
        AllowOverride All

        # Options Indexes MultiViews SymLinksIfOwnerMatch
        # AllowOverride Options FileInfo

        Order allow,deny
        Allow from all
    </Directory>
</VirtualHost>

Any help would be very gratefully appreciated!