I presume by "Autumn 2008" you are in the Northern hemisphere, i.e. 4-5 months have elapsed. In that case without a sitemap you should have 3-4M pages indexed unless your pages are heavy and the server is slow. Our main site has 2.5M pages and it took three months to index them all (without a sitemap). Until then we noticed what you are seeing -- if we did a selective site: command, we got 400k pages, which was also the count if we did a sitewide site: command. But once the pages were fully indexed, the site: operator worked as intended.