IIS Custom Error page and ColdFusion Url Rewrite question

Here's what I've done. I have a website setup that has only one physical page, index.cfm. All the links on that site are set up to be SEO friendly. Something like: domainname.com/my-coldfusion-question. I have set up a custom 404 page in IIS to include a coldfusion page called masterRewrite. When the page is called it parses the url, queries the database and builds a page that returns to the browser. So basically ANY link that one might go to on the site always returns a page with content and the browser never gets a "Page Not Found" error. So here's my question: When google spiders my page does it ever know that a 404 has occurred? I've tested a little bit myself by using cfhttp to go to a page that doesn't exist on the site and viewed the headers. The response header returned shows the same as a page that does actually exist. StatusCode is "200 OK." So my question is, does Google see this the same as a page that actually does exist? I originally thought that it did, but have noticed my page ranking is 0/10 and was wondering if somehow Google knows the difference despite the fact that the statuscode shows as 200. Any insight would be great, thanks. Michael

If the status code is 200 then Google does not know that it is a 404 error. I think they officially frown on this technique. What Google does is query a page that they know does not exist, and it they don't get a 404 they might punish your ranking. They also punish your ranking for having pages that are very similar in content under different URLs. I question the validity of using the page ranking metric as a measure of success. -Mike Chabot ----- Excess quoted text cut - see Original Post for more -----

Thank you, that answers my question.