Ok…
WordPress version: 3.3.2
WordPress SEO version: 1.1.9
I did this: Deactivated all plugins aside from Yoast SEO, Tried with the developer version and the issue still persisted.
I expected the plugin to do this: I expected my sitemap to be able to be submitted to Google Webmaster Tools without errors..
Instead it did this: GWT Produced this error once I submitted my sitemap:
We encountered an error while trying to access your Sitemap. Please ensure your Sitemap follows our guidelines and can be accessed at the location you provided and then resubmit.
Example:
General HTTP error: 404 not found
HTTP Error: 404