Page is a not externally linkable
-- Google SEO News and Discussion
---- Purposely returning 200 for Page Not Found instead of 404
johnnie - 1:07 am on Mar 22, 2009 (gmt 0)Thread source:: http://www.webmasterworld.com/google/3872472.htm
The canonical is issue is easily resovled using the rel=canonical tag. You could also return a 404 and do suggestions (or return search results based on the URL) on your 404-page.
Brought to you by WebmasterWorld: http://www.webmasterworld.com