Stefan - 3:58 am on Jan 15, 2006 (gmt 0)
Something that could be checked is possible canonical problems (my apologies if you know this already, but I didn't see a mention in your post). See if you have pages listed both with and without a www. A good way to do this is site:example.com -inurl:www . That will show listed URL's with no www. Then check site:www.example.com . That will show pages listed with the www subdomain. If you have pages listed two ways, it could be part of the problem.