Static 404 Page

I recently launched a WordPress site for Chez Pim, which is being hosted on Media Temple.

Everything is operating fairly smoothly except a few bugs that I’ve discovered in WordPress. One of them has to do with error handling (404 pages). Because she gets so much traffic, we’ve opted to remove the dynamic 404 handling from WordPress and turn it into a static html page.

This should be as simple as using the following code:
ErrorDocument 404 /404.html

Well that code doesn’t work no matter where I put it in the .htaccess file. It continues to use the custom 404.php template page from the WordPress theme.

Anyone have any thoughts on how to make this code work? I’ve cruised all kinds of forum posts already; none of them helped.

Here’s a peak at my .htaccess file:
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