I wish to apologize to subscribers of the RSS/Atom feed if some old posts have been reappearing in your newsreader.
I think the most likely explanation for this is that Blogger seems to regenerate the Atom/RSS entry when I add labels to old posts. Blogger has only recently introduced the ability to add labels to posts, so the older posts were unlabeled. I thought it would be useful to add labels to some of these older posts, but obviously not if it's going to annoy subscribers.
I probably need to find some other way to help people navigate the older stuff. I have also been experimenting with Squidoo. Other suggestions and comments welcome.
Squidoo has disappeared. Archive page is still available. POSIWID@Squidoo via WayBack Machine.
Updated 16 Feb 2016