First patch
Andrew Grumet: This patch catches 404 Not Found errors and inserts them into the standard error handling flow, which until now was just dealing with parser-generated errors.
This patch has been applied on feeds.archive.org. If all goes as planned, this will automatically propagate to atomenabled.org and feedvalidator.org in a matter of hours. Sourceforge propates all changes to the anonymous cvs servers every 5 hours.