Idont have 7.1 on my main site, but I'd estimate at least 3 on there; but i'm not concerned as I have a sitemap that automatically feeds my forum urls to google and yahoo.
Not for nothin', but even Google says the sitemaps are just guidelines/recommendations to help their crawl -- it's not a be-all, end-all index.
never said it was, but if you're feeding them URLs to crawl, you're giving them a basis to work with, vs letting them auto discover
