Blogger using feeds from AMO is having problems with feed entry duplication. "at least in my default aggregator (Thunderbird), the same feed entries are retrieved again and again; I receive each of them at least twenty times." I believe this person is referring to: https://addons.mozilla.org/en-US/firefox/browse/type:1/format:rss and https://addons.mozilla.org/en-US/thunderbird/browse/type:1/format:rss
Gen: Thanks for bringing this to our attention. I have commented on the blog you linked to. I have fixed this issue last month, but it has not been pushed to production yet (see the bug I am duping this to).