How many years did you register your domain name for?
If it's only one then that's a point against you in Google's eyes.
Why?
Because the majority of Spam websites only register a domain name for one year. A domain registered for a longer period implies that the owner is more likely to be legitimate and serious about their web site.
This is just one of the unusual factors now considered by Google when indexing and ranking a website. Factors you could never even have guessed at in some cases.
How do I know this?
Google have recently filed United States Patent Application 20050071741 on March 31, 2005.
In which many of the search giants secret ranking criteria is revealed and it makes very interesting reading. You have got to read this if you're serious about ranking well in Google. The days of Spaming Google are drawing to a close. With this patent they reveal just how hard they're coming down on Spam sites. You Do Not want to get caught out.
Via Robot Wisdom [1], “Great Site Ranking in Google The Secrets Out [2]”
I suspect Google [3] is doing this to help stem the tide of Google spam. By giving the search engine optimizers the guts of their Page Rank algorithm (or a good portion of it) they may be trying to say “Hey! Stop playing around with links and pages with loaded words—they won't work and here's why!”
But the suggestions made in the article are ones I pretty much already follow and has been common sense for quite a while now.
But those search engine optimizers—I suspect they needed a swift kick in the rear to get with the plan …
[1] http://www.robotwisdom.com/