On my WordPress install, I use the WP-SuperCache plugin to be nice to my web server. I was shocked when trying to show a coworker something on my site (he typed in whatanoob.com - what a n00b! :) ) to see my homepage content very old and the redirect was no longer working (it worked some time ago when I setup WordPress). It appears that sometime after installing the WP-SuperCache plugin, my website no longer redirects the aliased site to the "real" domain, but instead just serves up the same content (this is very, very bad for SEO). The redirect removing the 'www.' still worked.

The fix is simple.. I just added the lines:

RewriteEngine On RewriteCond %{HTTP_HOST} ^(www.)?whatanoob.com [NC] RewriteRule ^$ http://whatan00b.com/$1 [L]

.. to my .htaccess file.

Two lessons (re-)learned:

1. Test everything - This WP-SuperCache is definitely not something that you can install, activate, and expect to "just work" with your setup. When you assume.. well, you know the rest.
2. Monitor, monitor, monitor

FYI: still not sure why cache was so stale, but going into the plugin settings and deleting the cache cleared it up. I also changed it to clear cache whenever posting new posts.