title: I thought cross-subdomain AJAX requests were allowed, but this Chrome error seems to indicate otherwise
body: <p>I know that cross-domain requests are disallowed for security reasons, but I was under the impression that only the top-level domain needed to match, that different sub-domains were okay.  However, I am getting this error from Chrome 7:</p>
  
  <p>"Unsafe JavaScript attempt to access frame with URL <a href="http://foo.somedomain.com/dir/page.html" rel="noreferrer">http://foo.somedomain.com/dir/page.html</a> from frame with URL <a href="http://bar.somedomain.com/otherdir/otherpage.html" rel="noreferrer">http://bar.somedomain.com/otherdir/otherpage.html</a>. Domains, protocols and ports must match"</p>
  
  <p>What exactly are the rules for these types of requests?</p>