404 Error Problem

I’m trying to get a custom 404 page going on WordPress 3.9, using a child theme of twentyeleven (2011child). To my understanding, I’ve set the child theme up correctly, and have copied the 404.php from the parent twentyeleven theme to the child theme directory. If I put a bogus page id on the browser url line, like “http://mysite.com/test.html” (where test.html does not exist) I get a generic Apache “404 not found” error. The site in question is http://penguincomputerslv.com, Not sure exactly *what* I’m doing wrong…