<blockquote>

I am using the robots.htm file in the way I have believed was normal practice</p></blockquote>

I can't vouch for 'normal practice', but I for one have never seen this approach used before!</p>

Currently, in IE, I see an explanation page with a link to the 'non-JavaScript' version of the page at the bottom. But the non-JavaScript page turns out to be a redirect implemented in JavaScript, so I don't get any further. (Tip: JavaScript and meta-refresh are not good substitutes for real HTTP redirects.)</p>

How about linking directly to sitemap.htm from the explanation page instead? Or even better, including the sitemap in index1.htm as the noscript content?</p>