For the technodweebs out there who care what was wrong, read on:
I use Feedburner to redirect
Now that's all great and fine and all if you just stick either one of those URLs in your RSS reader, like I've been doing. However... Feedburner has these handy-dandy little icons (shown in the image to the left) that people who are not so familiar with the cutting and pasting of feed addresses can (and do) use to add the feed to their favorite reader. I'm an old-school guy, so I never use these. I probably should have.
When someone clicks on one of those icons (or chicklets, as they are sometimes called), they don't wind up subscribing to the Feedburner address. Nope. I set up feedburner with the option to pass in the address of the feed before the redirect takes place, so they have my domain name in their reader and not the Feedburner domain. And no, I'm not using the "better" way Feedburner makes available due to an issue at my host. But no matter. I screwed up very late in the chain, dropping an "n" from my domain name when I typed in the redirected feed URL. The effect? People who clicked on the little icons got an error.
And no one told me until today. So thanks again, Donna.
So Feedburner users? If you are using the Browser Friendly option, check your links. All of them. Save you my hassle!