Is web.config cached in your browser?

I know that sounds like a wierd question - but let me explain:

I posted an update to our website's web.config file to redirect any request for the homepage, to instead go to our blog, and the redirect worked fine:

      <location path="index.html">
            <system.webServer>
                  <httpRedirect enabled="true" destination="blog" httpResponseStatus="Permanent" />
            </system.webServer>
      </location>

But when I removed that line from the web.config and reposted the web.config to the website, it still redirected me to the blog whenever I tried to visit the index.html page.

Why?

I sent a support ticket to our web host asking them what could possibly be going on, but they wrote back and told me that they were NOT being redirected. They instead suggested that I clear my browser's cache and try again. I cleared the cache and it worked! No more redirect.

So my question is - why did clearing my browser's cache get rid of the redirect? Is IE caching the web.config file? I know that sounds crazy, but at the moment I can't think of any other reason?