Welcome to WebmasterWorld Guest from 220.127.116.11
[edited by: tedster at 2:47 pm (utc) on Mar 1, 2013]
Longest interval since the Panda #9 (Nov 18, 2011) to Panda 10 (Jan 18 2012).
Googlebot couldn't crawl this URL because it points to a non-existent page. Generally, 404s don't harm your site's performance in search, but you can use them to help improve the user experience.
this is from 2008!
My recommendation would be to make sure that this page returns 404, and then to let these errors settle down. It's fine to keep them visible in Webmaster Tools, you can also mark them as "fixed" if you prefer to keep a cleaner UI (the "fixed" status is just for yourself, it's not used by our websearch pipeline). Having pages that return 404 is fine, so I wouldn't worry about them showing up in Webmaster Tools.