The Blogger help pages are messy, many links are broken, SSL login fails miserably with old browsers, the feedback link without login doesn't work, etc. If you're looking for a blog hoster try to find a better service. I want the "blog-by-mail" feature available here, so it's my own fault.
Known issue, the application/atom+xml media type for the atom feed apparently degenerates into text/html after the first access. This might be a cache issue, resulting in a warning by the W3C validator: