Loading a page via DHTML isn't enough to avoid the issue where IE blocks the page from rendering. You also need to invoke the DHTML via setTimeout. This test page contains the following code:
function loadStylesheet() {
var link = document.createElement('link');
link.rel = 'stylesheet';
link.type = 'text/css';
link.href = '/bin/resource.cgi?type=css&sleep=4&t=1280588593';
document.getElementsByTagName('head')[0].appendChild(link);
}
setTimeout(loadStylesheet, 100);
The stylesheet is configured to take four seconds to download. If you load this page in Internet Explorer the page renders immediately while the stylesheet is downloaded in the background. To see IE's blocking behavior take a look at the DHTML stylesheet page.
For more information see my blog post: 5d dynamic stylesheets.