Sgt_Kickaxe - 4:14 pm on Jun 19, 2012 (gmt 0)
Obvious question: Is this absolutely and definitely unrelated to mod_speling?
It has nothing to do with mod_spelling. Wordpress has a canonical function that redirects pages to the correct url if you, for example, try to visit a shortened version or version with missing words/parameters. It does this quick check before returning a 404 error code and if it finds a likely suitor it redirects via 301 instead of serving the 404. The result is a lot of redirects for pages that have never and will never exist.
what exactly is a "manual redirect"?
When you assign an old url a 301 redirect code and point it to a new url. I do this manually via htaccess though there are some popular plugins that can do this for you.
Does WMT report where the shortened URLs are supposedly linked from?
No, it doesn't show where the url was linked from OR that it ever appeared in a sitemap file.
Added information: Many of the urls being reported in GWT are EXACTLY the same as the old ones with .. added to the end. I don't know why Google would be testing urls with a double period at the end of the url, or any other characters, but they are in GWT so...
I'd like to think none of this has any bearing on serps but from an SEO standpoint I don't want the extra 301's, and resulting 404's when I make changes, on pages that never existed.