I’m not an SEO expert by any means, but I don’t think the Google Webmaster Tools 404 messages are causing me any harm, other than to fill up the “crawler errors” report with entries.
In my particular case, this blog as moved a couple of times over the years, and I’m trying to do what I can do to clean up the 404 errors, most of which, like this one, don’t cause any particular harm, but are a bit messy.
Glad to hear there’s a noindex, follow on the pages.
I’m happy to just ignore the messages for the time being, and concentrate on the (many) more pressing issues I have as a part time WordPress administrator ;).
Thanks.