Having noticed an issue in Google Webmaster tools relating to a website running on WordPress, it seemed some default settings were causing these 404 errors to occur.
The 404 crawl errors were being created to /feed/ directories post page titles. After investigation it seems WordPress is rather bloating the header these days, and in the process is adding /feed/ etc into the header of each page!
To resolve this we used functionality within Yoast. I would highly recommend looking at the WordPress SEO by Yoast plugin http://wordpress.org/plugins/wordpress-seo/ .
In the Yoast settings, looking at the Titles & Metas screen, I would suggest that within “Sitewide meta settings” you look to enable “Noindex subpages of archives”, and also within the “Clean up the <head>” section, tick each option in order to remove the bloat from the head section.
After doing this the 404 issues within Google Webmaster tools were resolved.
If you have questions or would like help with your website, please do get in touch.