Dojo/Dijit: Can't get filtering select to work

Question

I have a page with some JavaScript and it includes dojo.parser and has parseOnLoad set to true and whatnot.

Later in the page, I have another JavaScript tag that has:

dojo.require('dijit.form.FilteringSelect');
dojo.registry.remove('ID OF SELECT BOX');

After all that, I have a select box with dojoType="dijit.form.FilteringSelect".

Whenever I load the page, I get:

undefined Could not load class 'dijit.form.FilteringSelect'. Did you spell the name correctly and use a full path, like 'dijit.form.Button'?

Any ideas why? If I put the require statement in the first JavaScript tag, it works (but that tag is in a more global file, so I don't want it there).