activeco - 12:27 pm on Feb 3, 2007 (gmt 0) This could be indeed a problem to some sites.
The second major change was that I indicated my domain as www to be my primary address, by clicking on that choice in my control panel.
Then yesterday, the sitemap was downloaded, and I immediately disappeared off the radar of google.
Be sure that your chosen primary root is the one Google already prefers in their results and that it is properly set on your server.
Be sure that your sitemap is made according to this above. Canonical issues are very easy to screw the things up.
This could be indeed a problem to some sites.